How to Write Music
For The Airband
LANGDON C CRAWFORD
Submitted in partial fulfillment of the requirements for the Master of Music in Music Technology
in the Department of Music and Performing Arts Professions in The Steinhardt School
New York University Advisors: Kenneth J. Peacock, Robert J. Rowe
[DATE:2006/12/21]
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Table of Contents:
0.0 Cover
0.1 T.O.C. ……………………………………………………………....01
0.2 Abstract …………………………………………………………….02
1.0 Motivation ………………………………………………………….03
2.0 History & Context ………………………………………………….04
3.0 The Airguitar: Hardware development …………………………….09
4.0 Airguitar Software………………………………………………….16
4.1 Control Maps………………………………………………..17
4.2 Signal Generators……………………………………………20
4.3 Signal Processors……………………………………………24
5.0 Instruments………………………………………………………….28
5.1 Rhythm Guitar………………………………………………28
5.2 Lead…………………………………………………………28
5.3 Techno………………………………………………………29
5.4 Shakey-Shakey……………………………………………...29
5.5 Rhythm Sampler…………………………………………….30
5.6 Tape Jockey…………………………………………………30
6.0 Deliverables………………………………………………………….31
7.0 Future Work…………………………………………………………34
8.0 Conclusion…………………………………………………………..35
9.0 Reference Materials…………………………………………………36
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Abstract
This paper describes the process by which a contemporary composer could write music
for above named electronic music performance ensemble, which employs some novel
interfaces for musical expression. To understand how to write music for this ensemble,
one should have an idea of how this ensemble came to be. I shall briefly discuss my
motivations for creating such novel interfaces and forming an ensemble, after which I
will go into the technical details of the fast prototyping process for the hardware
component (the air-guitars), and the current state of the ongoing development of the
software component of the instruments used in the ensemble. I will then describe the
current uses of these instruments in musical performance applications and how one may
write music to play on these instruments.
With a technical understanding of these instruments a composer may be able to
write whatever she pleases for the ensemble. But even without a deep technical
understanding of the tools, a composer could still deliver materials to the ensemble so
that pieces may be easily performed with minimal rehearsal. Examples of such
deliverables and all source code shall be included in the appendices of this paper for ease
of replication and modification by interested composers.
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Motivation.
My motivations for this project are completely selfish. I like electronic music. I like it a
lot. I have worked with Electronic Music Foundation for a number of years now and
continue to enjoy working with and around the electronic music world. There is one
major problem I have with electronic music: Tape music concerts.
Some of my favorite pieces of music in the electronic music cannon are tape music. The
early work of Stockhausen, “Williams Mix” and other tape pieces by Cage, are on my list
of great pieces of tape music. But I would walk out of a concert if these pieces were
played back via loud speakers. Defense of this opinion is outside the scope of this paper
and this topic is discussed with greater detail in other places [Rovan 1997 Wanderley
2000, Collins 2003]. When I go to a live I would like to see, hear and experience the
creation at least the human performance of music.
I also like rock music, rock concerts and theatre. At electronic music concerts I often
longed for the excitement and drama that I experience at these other perfomances. And
when at rock concerts and theatrical performances I often miss the diversity of sounds
available in electronic music.
So I decided to try to make a meeting of the best of both worlds. Inspired by the work of
several people in the electronic and computer music community who develop unique
methods of performing music [Allen 2005, Chadabe 1997, Cook 2001, Sunami 2006,
Waisvisz 2006, Weinberg 2004, Young 2002 ].
I was also inspired by the cultural phenomenon of air guitar playing. This is the playing
of an imaginary guitar using exaggerated gestures of strumming and such [Wikipedia,
2006]. These exaggerated gestures offered what seemed to me at that time an ideal
opportunity to gather gesture data via motion sensors and use that data to control
electronic music. This could potentially offer the performance energy and drama of rock
music while realizing the sonic possibilities of electronic music.
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Context.
I have been interested in gestural improvisation with electronics for some time. I have
developed a few control systems based on Joel Chadabe’s Solo, and one based loosely on
a dataglove paradigm.
The first successful system I developed was ‘Video Solo’. This system employed a
video-tracking program, using tools from SoftVNS2.0 by David Rokeby [Rokeby 2006].
This system was the first I developed that freed me from the mouse and keyboard control
paradigm. I could control the computer in limited ways by waving my hands in front of a
video camera. The video tracking software tracked the position of my hands (or any light
colored objects) along the two vertical edges of the video frame. The position was
mapped directly to control parameters, lower position in the frame output a lower value,
higher output position a higher value.
In early testing I made what I called a video Theremin. One hand controlled the
frequency of an oscillator the other controlled the amplitude of the audio signal. This
was my basic proof of concept. The video tracking worked fairly consistently as long as
certain technical considerations were met. These considerations included controlled
lighting and fixed camera exposure and focus settings.
In the next phase of development I tried to emulate Chadabe’s Solo, based loosely on his
personal descriptions and his papers [Chadabe, 1980, 2000, 2002]. One hand controlled
timbre of a Frequency Modulation (FM) synthesizer, which was driven by an algorithmic
note generator. The other hand controlled the tempo of the note generator.
In the last phase of development I mapped the hand positions to the continuous control of
two granular synthesis parameters. One hand controlled density of the grains. The other
hand controlled the amount of random variations in the values a number of several
parameters, which changed with each grain. Some of these parameters included grain
duration, pan position, and playback rate of granulated sample. In addition to the two
continuous controls there was a triggered event control. When the two hands were both
at the top of the frame a new sample would be randomly selected from a library of sounds
and loaded in to the granular patch. This allowed for a variety of sounds from very few
control parameters.
This instrument was fun to use for a while, but had several problems and limitations that
made it less than ideal for regular performance. One major problem was timing
resolution. I had to move my hands slowly for the video software to track their position.
This was do to a few factors, mostly the slow frame rate of my video tracking software.
The video input I used had a frame rate of approximately 30 fps. The motion sensing part
of the software compares sequential frames, which means at least two frames must go by
to get any meaningful position or change in position information from the software. At
15 accurate measurements per second, I had a time resolution of 67 ms at best. This
made precise musical timing very difficult if not impossible. Another timing issue is the
latency involved in digitizing video the input and transferring it to the computer over
firewire or usb.
Another major problem with my video tracking patch in softVNS2.0 is that it required
some control of the lighting environment. This is not such an issue in a concert hall
when there are hours to set up and the theatrical lighting can be dimmed so that the light,
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from a camera-mounted lamp, reflecting off my hands is the brightest object in the frame.
In other settings for example a gallery space with florescent and outdoor light leaking in,
my tracking software was not as consistent and very frustrating to try to use in
performance and presentations.
A few minor issues were related to portability. The video tracking used most of the CPU
time on a g4 500Mhz laptop, so the audio software in was controlling had to be rather
sparse. For more complicated sound generating routines another computer was needed.
This combined with the lights and stands for lights and cameras made the system difficult
to carry from show to show.
The next system I developed built upon the audio software from the first system and
replaced the video tracking and camera with a signal analysis patch and an Etherwave
Theremin. The Theremin outputs an audio signal where there frequency and amplitude
of a synthesized tone can be varied by moving one’s hands or body closer and further
from two antennae [MoogMusic 2006, wikipedia]. The signal analysis patch takes the
signal from the audio input of a computer and outputs continuous values based on the
estimated frequency and amplitude of a signal. These values are mapped to control
parameters of signal processing/ synthesis routines.
The Theremin control system solved a few of the problems present in the video based
system, introduced a few of its own problems and helped clarify what I needed to do in
future interface design projects.
The Theremin is a very responsive controller. Even when used to control the computer it
has very little if any perceived latency. Changes in hand positions have immediate effect
on the sound output from the computer. Compared to the video tracking system, the
Theremin less bothered by changes in the performance environment.
That being said there are some issues with using the Theremin as a controller. One is
that temperature and humidity have an effect on the capacitive response of the antennae
[Alford 1999]. From personal experience I can also say that the amount I am sweating
has a direct relationship with the response of the device. As I heat up and cool off during
a performance, I have to change my standing position relative to the Theremin. For
example in one performance I had to move from standing less than an arms length from
the device when I was cool to a step or two out of arms reach when I was sweating.
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The Theremin too provided the burden of transportation from show to show. I could fit
everything for this system except the computer into a hiking pack, which was great. But
these were much heavier objects than the video system. For consistent amplitude
tracking I had to use a microphone preamp and a passive DI box to connect the Theremin
to the audio input of the computer. (Note: I did not research the engineering of why a
longer cable run at line level would alter my amplitude readings) While this system was
portable enough for public transportation, it was still a burden and left me wanting a more
easily portable system.
Besides the technical and portability issues with the Theremin as a controller, I found the
lack of discrete controls in both the Theremin and video based systems somewhat
limiting. In some situations I used foot pedals to make program changes [fly by wire
v1.0 and v1.1] and other times someone would trigger program changes from the
keyboard while I was at the Theremin.
The limitation of the Theremin as a controller did not keep me from using it but did
inspire me to try something completely different.
My next interface project was based on a data glove paradigm [Sturman 1994, Sonami
2006, wikipedia]. The interface involved a gardening glove with sensors stitched on to it
and an analog to MIDI interface. This interface gave me the discrete control I desired
and the portability. There were continuous flexion sensors on the fingers and switches on
the fingertips and under the thumb. The glove and hardware were so small that they
could fit into the outer pocket of the case I used to carry my computer.
Performing with
my data glove.
At the NYU
adv. computer
music concert December 2005
Performing with the Etherwave Theremin as a
controller for laptop compositions with the Philippa
Kaye Company. March 2005
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But for all the gains in detailed control and portability, I lost the large gesture control of
moving my hands, arms and whole body in space. An additional issue with glove
controllers is ergonomics. I am not as comfortable with a glove on my hand as I am with
an object that I can pick up and put down. So again I move on to try to develop an
interface that has large form gesture control as well as discrete control of details and that
doesn’t require attaching anything to my body.
The Airguitar is my latest and most technically involve control system. This is also the
first project I developed as part of an in depth project for a gradate class on the very
subject of musical controllers. My aspirations were to allow a few of my favorite rock
music gestures, specifically the strumming of a chord on an electric guitar and the
overhead punch of the drummer striking the crash cymbals, to control or trigger
electronic music sounds and processes.
My technical inspirations came from the work of Burt Bongers and Perry Cook. Bongers
built the Lady’s Glove (version 4) and the Hands (version 2) [Sonami 2006, Waisvisz
2006]. Cook outlined principles of making musical controllers and discussed some
specific devices that he developed that directly influence my choice of sensors and how
they were used [Cook 2001]. While developing the Airguitar I also found several
resources on the web that deal with keyers “ A Keyer is a device for signaling by hand,
by way of pressing one or more switches” [wikipedia].
Having seen the Hands and the Lady’s Glove in live performances, I knew the musical
possibilities with such controllers. They had the gesture and detail control that I sought in
my own work and were wielded by experts who have been using these devices for many
years [Chadabe 1997, Waisvisz 2006, Sonami 2006]. The longevity of these interfaces
Two versions of the hands [Waisvisz 2006] Version 2 on left, current version below.
The Ladies glove.
Right: photo by Joel Chadabe. Below: photo from www.media.mit.edu
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made me think that they were excellent tools to model. The devices Cook described in
his paper, Principles for designing computer music controllers, have also had staying
power. He presented these devices to the NIME class at ITP in the spring of 2006 at 5
years after they were initially discussed in is paper [Cook 2001]. While these devices
where developed several years ago Cook still finds musical use for them. In developing
the Airguitar I sought to create a device that would work as well as these devices, such
that I would want to use the Airguitar for a long time.
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3.0 The air guitar
The first prototype of the air guitar was very simple. It allowed for the triggering of
sound, of which 8 sounds could be selected. The interface was comprised of two
components; One keyer, which represented the frets in the left hand and one switcher,
which represented the pick in the right hand.
The keyer was a small box with 6 push buttons mounted on it. One button was placed
under each finger, one extra under the middle finger and one more under the thumb.
There were 2 samples associated with each finger button. The position of the thumb
selected which of the 2 samples would be called when a finger pressed down. The
switcher was a small box with a toggle switch mounted on it. When the toggle changed
state, it would trigger the play back of a sample called by the left hand. The switcher
could be held in one hand and manipulated with the thumb and fingers, but I preferred to
strap it to my belt so that I could quickly flip the switch back and forth.
Above Left: Botton based Keyer for original prototype Above Right: Switch attached to belt
While this may have been a start and a proof of concept, that buttons and switches could
potentially rock, it was much too limiting. I could play simple rhythm guitar parts
consisting of a few notes of fixed duration and that did not require any continuous
variation such as volume or timbre.
The technical implementation was quick and dirty. The devices connected to a analog to
midi converter circuit under my clothes and a MIDI cable kept me tethered to my
computer. It was not so comfortable to wear around the house, and took some time to put
on before giving a presentation.
Above: analog to midi converter and early Airguitar.
There were also coordination issues for me as a performer. When playing this air guitar I
would often trigger a sample just a few milliseconds before I had put my fingers in the
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right position to call the sample I wanted. This motivated me to quickly move from
triggering samples to controlling a synthesis routine, that could be triggered and pitch
could be changed independently.
The most obvious synthesis routine for this project seemed to be a plucked string model.
I developed a pseudo plucked string model using a Max/MSP, based on the Karpus-
Strong Algorithm.
The Karplus-Strong Algorithm (KSA) uses a feedback loop where the period of the delay
is the inverse of the fundamental frequency of the string model. A high feedback
coefficient causes this string to resonate when excited. KSA also uses a FIR filter such as
feedforward delay, [z^-1] in the feedback loop to simulate the natural dampening of high
frequencies over time. KSA describes the excitation of the string model as filling the
delay buffer with random values (white noise). [Smith 2006, wikipedia]
Figure: Block diagram of the Karplus-Strong Algorithm [Smith 2006]
At first I did not use this algorithm, as I didn’t know much about filter design, and was
trying to follow one of Cook’s principles; “sound now subtletly later”[Cook, 2001].
Instead I used the Max/MSP implementation of a feedback comb filter [comb~]. A
feedback comb filter is a IIR filter, which adds a delayed version of its output back into
the input to the filter. This causes constructive and destructive interference at evenly
spaced intervals in the frequency domain. [Smith 2006, wikipedia]
Figure: block diagram of a comb filter [Smith 2006]
Using a high enough feedback coefficient causes the filter to resonate with peaks at
frequencies harmonically related to the inverse of the period of the delay. I took
advantage of this in my attempts to create a sound similar to a plucked string. [Crawford,
2006]
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The Max/MSP implementation of a comb filter [comb~] contains a feed forward delay at
the input but not in the feedback loop itself. This is where [comb~] differs from the
KSA. Rather than sounding like a plucked string when excited [comb~] outputs a sound
more like a standing wave in a tube. While not completely satisfied with this algorithm,
it worked well enough to inspire some significant modifications to the hardware device.
This routine required continuous controls to be used in performance. Specifically, the
amount of feedback used in the delay loop controlled how long the filter would resonate
after and impulse was passed into it. Also the timber of this instrument could become
tiresome very quickly with out some subtle changes in tone. The buttons on the keyer
could be used to change the delay time (therefore the pitch) of the filter and the toggles
on the switcher could trigger an impulse. But without out any continuous controlled I
was at a loss.
The next development of the air guitar addressed the control needs of this synthesis
routine. The devise built this time had a few continuous controls in the place of
switches. A keyer was used for the left hand again. This one was built in and around a
piece of PVC pipe, specifically a 90º 2.5” corner fitting.
Above Left:PVC pipe with top surface filed flat for mounting FSRs Above Right: Analog to MIDI convert that fits inside the PVC fitting.
This pipe fit comfortably in my hand, much more comfortably than the box of the
previous design. Low profile Force Sensing Resisters (FSRs) were used in place of
buttons. A small analog to MIDI converter was placed inside the pipe and powered with
a 9-volt battery.
For the right hand, I developed a plucker. The first round involved a flexion sensor
mounted perpendicular to a flat surface so that I could flick it with my thumb or finder to
trigger an event. Also mounted on this surface were a few FSRs. I planned to use these
for continuous control of feedback and filtering parameters. Mounted on the underside of
this surface was a dual axis accelerometer, which was used also to trigger an event. Also
mounted on the underside were another analog to MIDI converter and a 9-volt battery.
- - 12
Above Left: Plucker top surface, FlexSensor and FSR strips. Above Right: Plucker internal workings, ADC, two axis Accllerometer
While the plucker allowed for the continuous control I needed for the synthesis routine, I
was not satisfied with the keyer. Each button on the keyer was associated with a specific
pitch. 8 buttons could be used over the range of an octave using a diatonic scale.
Above: 8 FSR Keyer, 0.5 inch diameter on top, smaller diameter sensors on the side. Strap made of electrical tape goes around back of thumb.
I wanted a lot more pitch options. So I remapped the device considerably. Rather than
one pitch per button over 8 buttons, I used only four buttons in combination. I did this
for two reasons. Keeping the fingers in one position made the device easier to play with
less hand fatigue, and with the combinations of 4 buttons I had 16 discrete values.
Based on a few pictures and diagrams of cord keyers see images below I decided also
mount two buttons again under the thumb. With these thumb buttons changing the state
of the finger values I now had a range of 48 discrete values. This allowed for an
improved expressive range. But when mapped to notes in a 12-tone octave, the finger
positions were different for the same note over the 48 values. This made memorizing the
finger positions and accurately playing pitches so difficult that decided to scale back the
range. Instead of each thumb position shifting the finger pattern by 16, I made it just
shift by 12. The range would then be 40 discrete values. But the finger patterns were the
same. Making memorization much easier and my playing more accurate.
Far Left: Septambic Keyer
[Mann 2006, wikipedia]
Near Left: Twiddler2 [Mann 2006, wikipedia]
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Finger Chart for Keyer: 1 = FSR pressed, 0 = Not pressed
indx mid ring pnky t.Low t.High num Pitch indx mid ring pnky t.Low t.High num Pitch
0 0 0 0 0 0 0 c 0 0 0 0 0 0 0 c
1 0 0 0 0 0 1 c# 1 0 0 0 0 0 1 c#
0 1 0 0 0 0 2 d 0 1 0 0 0 0 2 d
1 1 0 0 0 0 3 d# 1 1 0 0 0 0 3 d#
0 0 1 0 0 0 4 e 0 0 1 0 0 0 4 e
1 0 1 0 0 0 5 f 1 0 1 0 0 0 5 f
0 1 1 0 0 0 6 f# 0 1 1 0 0 0 6 f#
1 1 1 0 0 0 7 g 1 1 1 0 0 0 7 g
0 0 0 1 0 0 8 g# 0 0 0 1 0 0 8 g#
1 0 0 1 0 0 9 a 1 0 0 1 0 0 9 a
0 1 0 1 0 0 10 a# 0 1 0 1 0 0 10 a#
1 1 0 1 0 0 11 b 1 1 0 1 0 0 11 b
0 0 1 1 0 0 12 c 0 0 1 1 0 0 12 c
1 0 1 1 0 0 13 c# 1 0 1 1 0 0 13 c#
0 1 1 1 0 0 14 d 0 1 1 1 0 0 14 d
1 1 1 1 0 0 15 d# 1 1 1 1 0 0 15 d#
0 0 0 0 1 0 16 e 0 0 0 0 1 0 12 c
1 0 0 0 1 0 17 f 1 0 0 0 1 0 13 c#
0 1 0 0 1 0 18 f# 0 1 0 0 1 0 14 d
1 1 0 0 1 0 19 g 1 1 0 0 1 0 15 d#
0 0 1 0 1 0 20 g# 0 0 1 0 1 0 16 e
1 0 1 0 1 0 21 a 1 0 1 0 1 0 17 f
0 1 1 0 1 0 22 a# 0 1 1 0 1 0 18 f#
1 1 1 0 1 0 23 b 1 1 1 0 1 0 19 g
0 0 0 1 1 0 24 c 0 0 0 1 1 0 20 g#
1 0 0 1 1 0 25 c# 1 0 0 1 1 0 21 a
0 1 0 1 1 0 26 d 0 1 0 1 1 0 22 a#
1 1 0 1 1 0 27 d# 1 1 0 1 1 0 23 b
0 0 1 1 1 0 28 e 0 0 1 1 1 0 24 c
1 0 1 1 1 0 29 f 1 0 1 1 1 0 25 c#
0 1 1 1 1 0 30 f# 0 1 1 1 1 0 26 d
1 1 1 1 1 0 31 g 1 1 1 1 1 0 27 d#
0 0 0 0 0 1 32 g# 0 0 0 0 0 1 24 c
1 0 0 0 0 1 33 a 1 0 0 0 0 1 25 c#
0 1 0 0 0 1 34 a# 0 1 0 0 0 1 26 d
1 1 0 0 0 1 35 b 1 1 0 0 0 1 27 d#
0 0 1 0 0 1 36 c 0 0 1 0 0 1 28 e
1 0 1 0 0 1 37 c# 1 0 1 0 0 1 29 f
0 1 1 0 0 1 38 d 0 1 1 0 0 1 30 f#
1 1 1 0 0 1 39 d# 1 1 1 0 0 1 31 g
0 0 0 1 0 1 40 e 0 0 0 1 0 1 32 g#
1 0 0 1 0 1 41 f 1 0 0 1 0 1 33 a
0 1 0 1 0 1 42 f# 0 1 0 1 0 1 34 a#
1 1 0 1 0 1 43 g 1 1 0 1 0 1 35 b
0 0 1 1 0 1 44 g# 0 0 1 1 0 1 36 c
1 0 1 1 0 1 45 a 1 0 1 1 0 1 37 c#
0 1 1 1 0 1 46 a# 0 1 1 1 0 1 38 d
1 1 1 1 0 1 47 b 1 1 1 1 0 1 39 d#
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On the plucker I had one FSR that acted as an octave shift, much like the thumbs on the
left hand. This was needed when the keyer only output a small range. But with the keyer
outputting a range of 3+ octaves, the octave shift became a bother. The string model I
was using did not sound as rich or sustain as well in the upper octaves as it did in the
lower octaves. So the octave switch on the right hand became a synthesis switch. When
that FSR was pressed it would trigger a sustaining sound. When released the sound
would fade away. The left hand could control the pitch of this sound, and could thus be
used to play a sort of lead line.
At this point I had a fun instrument to play. I could go from rhythm to lead guitar with
just a slight change in hand position and had enough control of the sound and timing of
things that I could play some simple parts along with a prerecorded drum track.
Less regular and syncopated parts were still very difficult to play with these devices. The
plucker specifically had its limitations. The flexion sensor on the plucker had to be
slowly “cocked” back to prepare to be quickly moved on an upbeat.
For the time being though I was willing to accept these limitations. My main concern
was that I remained tethered to a midi interface and the computer via MIDI cables. I
wanted to be wireless.
In brief I will say this did not work well. I should have listened to Perry Cook “Wires are
not that bad (compared to wireless)”[Cook 2001]. To keep development time to a
minimum all the gesture mapping, was handled in the software on the computer, rather
than in the firmware on the micro controller in the analog to MIDI circuit. This means
that when using MIDI there is a minimum system latency of 8 milliseconds when all the
channels of one controller are in use. For what I was doing 8 ms is not too bad. But this
is using a baud rate of 31250bps. The wireless transmission technology I could afford at
the time of this prototype worked somewhat consistently at a baud rate of 2400 bps. So
transmissions were 13 times slower, leaving me with a system latency of 100 ms or more.
Above Left: Wireless transmitter instead of midi plug, the yellow coil is an antenna.
Above Right: Wireless receiver connected to a pic [microchip, 2006] running serial to midi
For ambient electronic music this would probably be acceptable, but for a rhythm
instrument, 100ms feels like an eternity. In addition to the latency issue was the problem
that the wireless connection would drop out for a few moments every so often. This
made playing with any rhythmic precision nearly impossible. So I went back to the
hardwired solution.
- - 15
With the Airguitar working fairly well when connected via MIDI cables, I decided to
make another air guitar to play air bass or air keyboard parts along with the recorded
drums and live air guitar. This controller would have two keyers, the right hand would
mirror the left. With out a specific plucker device, triggering of events would be handled
by accelerometers mounted inside the PVC housing or by pressing the key on the right
hand. This keyer pair with two-axis accelerometers in both hands became what is now
the latest version of the air guitar.
Above: The latest AirGuitar controllers. 6 FSRs 2 axis accelerometer, midi out. Strap made of electrical tape for
now, goes around back of hand.
The Air guitar connects with the Max/MSP via MIDI
continuous control. Each analog to digital converter pin
on the pic chip is assigned a MIDI continuous controller
number on channel one. The patch below receives the
MIDI control data, displays the change in data over
time and sends the data out as a list. This patch may be
used in multiple instances. As it takes an argument for
the port letter associated with a MIDI interface. The
port letter is then mapped to an integer value via a look
up table, and all the [ctlin] object in this instance of the
patch will only listen to control data coming into the
assigned MIDI port. This allows for each device to run
the same exact MIDI code. This is convenient for
developers and performers. Only one program need be
coded, compiled and written to the pic chip. Left-
handed players may use these instruments with out any
reprogramming. One only needs to switch the plugs so
that the left hand plugs into port B and the right hand
plugs into port A of the MIDI interface.
- - 16
4.0 Software
This chapter describes the mapping, signal generation and digital audio effects used in the
Airband performance patch. The Airband patch uses 297 instances of 44 abstractions
created by the author for the Airband and other projects. Each patch developed
specifically for the Airband and some other sub-patches used extensively in the Airband
patch are pictured and explained below.
- - 17
4.1 Control Maps
[tab.4bit]
This patch takes the continuous controls from four FSRs, one under each finger, and
maps them to a single numeric output based on a 4bit word. It does this by first
considering each continuous control signal to be a binary integer (bit) value (1 or 0). The
state of this bit value is set when the continuous control signal is above or below a preset
threshold. Once each continuous value is set to a bit, the 4 bits are each scaled by a
power of two and summed to form a single number in base ten. [See chart in hardware
chapter].
[tab.4bit++]
This patch uses the two FSRs
under the thumb to transpose the
output of the 4bit patch. The
FSR on the inside of the curve
(thumb low) of the pipe,
transposes the output by an
octave (12nn), the FSR on the top
of the curve (thumb high)
transposes the output by two
octaves (24nn). [See chart in
hardware chapter]
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[tab.xltobang]
This patch takes the continuous control from the accelerometers and outputs a trigger
(bang). It measures direction change on one part of one axis of acceleration. It uses a
scaling factor to ignore changes in direction that involve small amounts of force, such as
vibrations and slow movements. It requires a rather quick and/or forceful motion to
produce a large enough number such that the change in direction is detected. The part of
the axis of acceleration, which is not measured, is reserved for rests, in order to prevent
accidental triggers.
[tab.tiltparam]
This patch takes the continuous control from the accelerometers and outputs a normalized
continuous control value such that the minimum tilt and maximum tilt are 0 and 127
respectively. The output is passed through [lang.smooth] to interpolate between
sequential measurements, as there are large jumps between the adjacent tilt values.
- - 19
[tab.tilttovol]
This patch is designed to work in conjunction
with [tab.xltobang] This patch works much like
[tab.tiltparam] in that it outputs a range of
values from 0 to 127, based on continuous tilt
measurements, but it only measures half of an
axis of acceleration, such that the range that
will not cause a trigger will be at minimum
volume. Interpolation is used to smooth
changes in quantized control data. Fast
movements use minimal interpolation where as
slow movements use long interpolation times.
This helps volume control be both sensitive and
bold.
[tab.PitchMap]
This patch uses [tab.4bit++] and one axis of
acceleration to output a pitch with vibrato
(float). The integer pitch value from
[tab.4bit++] is also output along with the unused
axis of acceleration.
[tab.pulserMap] (figure on next page)
This patch maps the FSRs to a control a clock. Using gates in various combinations
different regular rhythms may be generated, based on a preset tempo in BPM where the
time signature is 4/4. For example the index finger FSR set to high turns on the clock
and has it output quarter notes, the middle finger FSR set to high outputs 8th notes, both
together output 16th notes, and so on. This patch also incorporates [tab.xltobang], such
that when no keys are pressed, irregular rhythms or one shots may be triggered. The on
used axis of acceleration and the thumb controlled values are passed out of this patch to
be used with signal generators or effects, if needed.
- - 20
Above: [tab.pulserMap] patch Below: [tab.nnSynthMap] patch
- - 21
[tab.nnSynthMap]
This patch uses [tab.PitchMap] on the left hand along with [tab.4bit] and [tab.tilttovol]
on the right hand as a generalized monophonic synthesizer control scheme. [tab.4bit] is
used to control the on/off gate for the amplitude output, as well as to set a transposition
factor. The current transposition mapping is as follows: Index: no transposition
Middle: one octave
Ring: three octaves
Pinky: five octaves
All: 7 octaves
When more than one finger is pressed the highest possible transposition value is output.
With the transposition and three octave range of [tab.4bit++] this mapping routine has
and output range of 10 octaves. [tab.tilttovol] controls the output amplitude, when the
on/off gate is open/on. The right hand thumbs and one axis from each hand are passed
out of this patch for use with effects or other continuous controls for the synthesizer.
- - 22
4.2 Signal Generators
[tab.electricGuitar]
The next development in the Airguitar
software was a synthesized guitar sound,
which had several continuously
controlled parameters. At the core of
this patch is a rough implementation of a
plucked string model. This subpatch
based on the Karplus-Strong Algorithm
replaced the [comb~ ] object used in
earlier implementations of the Airguitar
(see KSA vs Comb~ discussion in
chapter 4). This string model is
separated into to main components, an
exciter and a resonator. The resonator
is the core of this variation of the KSA.
The exciter usually used in KSA
involves filling the delay buffer with
random values, essentially white noise
[Smith, 2006]. I don’t care much for
the initial burst of white noise heard
with this technique. So instead I use a
filtered impulse to excite the resonator.
Once this string sound is produced it is
lowpassed and distorted with a
waveshaping filter called [overdrive~].
This filter creates an effect similar to that of an overdriven tube amplifier [cycling74,
2006]. The pitch controls for this patch may be interpolated at the signal rate to produce
glissando and smooth trill effects. Dampening is mapped in this patch to reduce the
distortion, reduce the feedback coefficient in the resonator patch and lower the cutoff
frequency of the lowpass filter between the impulse generator and the resonator patches.
- - 23
[lang.igroov~] as used in [tab.loopSynth~]
[tab.loopSynth~]
This patch uses short percussive sounds as the sample material for a table lookup
oscillator. This patch uses the groove~ object with a loop synced window, to prevent
clicks at the beginning and end of a loop. Controlling the loop length, rather than
playback rate sets the pitch. Signal rate interpolation of the changes in loop length can
create glissandi effects. To play a high-pitched sound the source signal must have a lot
of energy at the very beginning of the loop. Percussion samples work well for this. A
convenient artifact of using loop length instead of play back rate is that high frequencies
are rolled off as even percussive sounds have less energy at the onset than they do just a
few milliseconds after the onset.
Also since this patch can use the same source material the sounds in this instrument
easily match the pallet of the sounds produces with the looping and sample playing
patches.
- - 24
[lang.jmsl.multisampler~]
This patch is a poly~ abstraction from a collection of code for using the Java Music
Specification Language (JMSL) to control Max/MPS[Didkovsky 2006]. These objects
may also be used with out JMSL. This patch takes a note number and trigger as input,
and outputs a sound. This patch may be polyphonic, with up to 16 voices simultaneously
sounding. Samples are indexed within one audio file. The patch then assigns one index
location per note up to 127 different index values (zero is reserved for rests/silence). This
patch also includes volume control, such that the trigger is not just a bang, but an integer
value. The volume is set when the note is triggered and cannot be continuously
controlled afterwards.
[lang.jmsl.singlesampler~]
This patch works very much like multisampler, except that it uses only one sound. This
sound is transposed across the keys, with middle c being the original playback rate. Notes
below middle c transpose the playback rated down by half steps, such that one octave
lower than middle c plays the sound half as fast, thus it sounds an octave lower. The
notes above middle c transpose the sound up by half steps.
- - 25
Above: [tab.dj.xfade2~]
[lang.dj.xfade2~]
This patch takes a three-item list as an input. The items are: file name, loop state, cross
fade time, and outputs an audio signal. The file name calls a file to be played from disk.
Loop state sets the file to play as a loop or play one time. Cross-fade time sets how long it
takes the new sound to fade in and the old sound (if any) to fade out. Only two voices
may be played simultaneously.
- - 26
4.3 Signal Processors
[lang.delloop~]
This patch takes a any audio input records a section into an delay buffer with an input
gate and a feedback gate coordinated such that a loop may be sampled and repeated with
out build up caused by continuous input. This loop will play until it is time for a new loop
to be sampled. Each time a new loop is sampled the delay buffer is clear so that no
residual signal from the previously sampled loop will be present in the new sampled loop.
[lang.samp&buzz~]
This patch a similar to [lang.delloop~]
It uses a buffer~ and groove~ combo
rather than a delay buffer. And its
loop playback is finite. The loop
length either becomes longer or
shorter for each repetition of the loop
depending on an optional argument.
If the loop length becomes shorter,
the sound output is a rhythmic
acceleration that continues into a
pitched glissando. If the loop starts
gets longer (it must start very short)
the sound output starts with a pitched
glissando and continues into a gradual
ritardando. The sounds stops when it
reaches present long and short
extremes of loop length.
- - 27
[tab.resonator~]
This patch is a resonant low pass filter. It takes a signal to be filtered, and two
continuous control parameters; cutoff frequency and resonance. The resonance is limited
to ranges such that the filter does not self oscillate. The control inputs are interpolated at
the signal rate so that changes in cutoff frequency and resonance do not cause clicks.
[lang.pingpongdelay2~]
This patch takes a mono or stereo signal and outputs a stereo delayed signal. There are
two delay buffers, one output for each channel. There is a feedback network such that the
output of one channel is fed back into the input of the other channel. The delay times of
the two buffers and the feedback level may be set as arguments or may be continuously
controlled.
- - 28
5.0 Instruments
Together synthesis routines and controller maps formed a variety of instruments. I refer
to these combinations as instruments as they suggest or were inspired by certain gestures
and approaches to playing. While many instruments were tried and tested during the
development of the Airguitar and the formation of the airband, I will focus on
instruments that are in regular use at the time of this writing. These instruments include
Rhythm Guitar, Lead, Techno, Shakey-Shakey, Rhythm Sampler, and Tape-Jockey.
5.1 Rhythm Guitar
The rhythm guitar instrument employs the [tab.pitchMap] and [tab.Pulser] mapping
routines to control [tab.electricGuitar~] and [tab.resonator~]. This is instrument and
previous versions of this instrument have been in use the longest. It was the first of these
instruments to take advantage of the guestural possibilities of playing an electronic music
instrument with the “air guitarist” gestures I adore. Played in the lower register the sound
is very rich and dense, which works well for the rock guitar sounds and gestures. Played
with a little dampening and combined with a regular sequence of triggers from
[tab.pulser] very basic rhythm guitar parts can be reproduced.
This instrument can also be use for sounds and styles other than guitar and rock. Played
in the top register with a small amount of dampening the sound is short and thin. I use
this method along with a slow moving filter sweeps on [tab.resonator] for playing rhythm
parts in a techno song for example.
5.2 Lead
The lead instrument employs the [tab.nnSynthMap] mapping routine to control
[tab.loopSynth~] and [tab.resonator~]. This instrument is often used with
[lang.pingpongdelay2~]. While this instrument was originally to play sustaining lead
guitar line over the rhythm guitar parts, this instrument is may be used to play almost
anything. It has a frequency range that covers bass thru treble instruments. Its range is
wide enough so that 3 people perform with it in different registers with out overlapping.
The pitch and rhythm controls are direct. They are not mediated by a control mapping
such as [tab.pulser]. The notes are either on or off depending on the state of the fingers
on right hand keyer. Notes may be faded in and out with [tab.tilttovol] but must be on the
entire time.
The [tab.resonator~] patch is key to performing with this instrument. In one piece for
example, we each pick a note of the overtone series of C, and we stay on that note while
varying the cutoff and resonance controls (exploring the overtones of that note). In this
piece we all play with different delay time and feedback settings for
[tab.pingpongdelay2~] . With feedback coefficients between 0.2 and 0.6 we can create
and control a layered sound as gestures add to the delay loop. With higher feedback
coefficients we can have an even more layered sound but some control is lost as sounds
remain in the delay loop for several seconds if not minutes.
This instrument may be one of the easiest to learn to play, as the mapping feels obvious
once the somewhat arbitrary 4bit mapping to pitch scheme is memorized. But with its
range and direct mapping it can also be very frustrating. One can be in the middle of
- - 29
playing a bass line and slip into a register five octaves higher. There is one piece where
we take advantage of this. We refer to the piece as the R2D2 duet. In this piece we
squeak, squawk, beep, buzz and whine back and forth as if having a conversation in the
language of the R2 units from “Star Wars”.
5.3 Techno
This instrument employs six [lang.delloop~] patches and two [lang.samp&buzz] patches
as well as one [tab.resonator~] patch for each hand. The delloop and samp&buzz patches
are controlled directly by the FSRs under the fingers and thumbs. The thumb high FSR,
controls the volume of the direct signal passing thru the techno patch. The thumb low
FSR selects between bank one and bank two of delloop patches and samp&buzz patches.
The finger FSRs control the volume of the recording and volume of loops. When a finger
FSR is pressed a loop is recorded and can be faded in and out. When the FSR is released
the loop stops. Each loop is set to repeat at a different subdivision of a master loop
duration that is passed to the techno patch.
The sampled loops are summed and passed to the dry output (though amplitude scaled by
0.5) and to [tab.resonator~]. The dry output and resonated output are soft panned such
that the resonated signal for each hand is panned towards that hand and the dry signal is
panned to the opposite side.
As this instrument does not generate signal it must be used in conjunction with a signal
generator. [lang.dj.xfade2~] provides the input audio in the latest version of the Airband
patches. Whenever a new tape cue is played, a tempo setting associated with the new cue
must be passed to techno.
Techno gets its name from its effect on the input signal. It can turn most any audio
source from spoken word, to drum tracks, to abstract field recordings into rhythmic
material on the fly.
Techno can create a variety of drum fills and transitions. Its is especially effective for
transitions from one rhythmic tape cue to another. For example, several sub loops of a
main loop may be played at once, while [tab.resonator~] provides a filter sweep just as a
new tape cue is dropped right on the down beat of the next measure.
5.4 Shakey-Shakey
This instrument employs [tab.4bit++] and [tab.xltobang] to call and trigger samples with
[lang.jmsl.multisampler~]. The two axis of tilt from each hand are mapped to control
volume and transposition. The transposition control allows for one sample in the multi-
sample bank to be played at different playback rates, thus providing for many sound
possibilities. This instrument has both hands controlling their own sounds. Such that one
hand can be triggering a percussive sample bank, while the other could be triggering a
collection of pitched samples, for example. This instrument is often used in conjunction
with [lang.pingpongdelay~] to create abstract textures, as triggers samples are layer both
with polyphony and with long delay loops with high feedback coefficients.
This instrument can be fun to play as it feels physically much like playing a shaker
instrument, such as maracas, while the sounds produces can be almost anything.
- - 30
5.5 Rhythm Sampler
This instrument works very much like the Rhythm Guitar instrument with one major
difference. The signal generator is a polyphonic sampler instead of a string model and the
duration of each note is fixed when it is triggered, and cannot be shortened later. The
same FSR that affects note duration in the rhythm guitar affects note duration for this
instrument. This patch was originally developed with multi-sampler, but it was too
confusing to use in a meaningful way with different sounds. With one sample mapped to
pitches this patch was much easier to learn to play in a few short rehearsals.
This patch is great to use with fixed duration bass samples, as a rhythm bass instrument.
While the [tab.resonator~] patch is used here too, it has little affect on bass samples
except to change the tone of the attack transients.
5.6 Tape-Jockey …
This instrument employs [tab.4bit++] to [tab.xltobang] to control [lang.dj.xfade2~] as
well as the system presets. This instrument is always available as a quasi-mode. A
quasimode is allows for the benefits of a mode with out the cognitive burden of
remembering which mode the system is in [Wikipedia, Raskin 2000]. A sustain pedal
accesses this quasimode. When the pedal is engaged the right hand selects a tape cue or a
system preset, the left hand triggers the cue or preset. The presets include effect settings
for [lang.pingpongdelay2~], which instrument is playing and what tempo the rhythm
instruments and techno should reference. The first two octaves of the 40 note range are
reserved for tape cues, one of these cues is always a silent cue so that rests may be
triggered. These cues can change with each song. The last 15 notes are reserved for
system presets. These presets are the same for every song. Examples of system presets
and tape cues can be seen in the next chapter discussing scores and deliverable materials.
This instrument allows for realtime playback of any tape music piece. The piece could be
segmented into several shorter sections of the entire piece which one person could
perform. Or the piece could be decomposed into several separate tracks or stems each
segmented into short sections, which an ensemble perform and rearrange as desired.
The next chapter will describe how a composer could produce instructions and audio files
for the Airband to perform a tape music piece.
- - 31
6.0 Deliverables
The Airband can play music described by composers in several ways. When limited to
the Lead and Rhythm guitar instruments a composer can describe the musical her piece
entirely with common music notation. When using the other instruments, sound files
must be supplied in addition to written parts. When using Shakey-Shakey or TapeJockey
(a requirement for Techno), index files must be supplied in addition to audio files and
written parts. These index files describe how the software will playback the multi-sample
banks in Shakey-Shakey, and describe a variety of details in TapeJockey, such as audio
playback controls, tempo settings and effects presets.
The pitch range of the Lead instrument is from the C three octaves below middle C to the
D# 7 octaves above middle C. This range corresponds to the MIDI note numbers 24 to
135, and fundamental frequencies of 32hz to approximately 20kHz.
The pitch range of the Rhythm Guitar is from the C three octaves below middle C to the
D# above middle C. This range corresponds to the MIDI note numbers 24 to 63 and the
fundamental frequencies of 32hz to 311hz.
Audio files are assumed to be 16 bit audio sampled at 44.1kHz saved as aiff or wave.
Audio delivery of samples in other TapeJockey assumes all files are stereo. Mono files
will be played only out of the left channel. Shakey-Shakey and RhythmSample assume
sample files to be mono. Only the left channel of stereo sample files will be used.
Below are some examples of scores successfully used in performance with the Airband.
One might notice that structures are loose in these scores. At the time of this writing the
Airband was moving from freely improvised music exclusively on the pitched and
sample based instruments (lead, rhythm guitar, shakey-shakey and rhythm sampler) to
playing more structured compositions which incorporated the long sound file and effects
based instruments (tapejocky and techno).
- - 32
for
refe
rence o
nly
Cue N
um
ber
com
ma
tape,
fx, in
str
file
nam
e,
on/o
ff,
instr
num
ber
loop o
n/o
ff,
dela
y1,
tem
po (
if a
pplic.)
xfa
de t
ime, dela
y2
tem
po,
feedback
scale
sem
icolo
n
C 1 , tape silence 0 100 120 ;
C# 2 , tape FuegRptLow.aif 0 100 120 ;
D 3 , tape FuegRptNoiseBig.aif 0 100 120 ;
D# 4 , tape FuegRptNoiseSml.aif 0 100 120 ;
E 5 , tape NOISE.AIF 0 100 120 ;
F 6 , tape NOISE3.AIF 0 100 120 ;
F# 7 , tape LITTLE.AIF 1 100 120 ;
G 8 , tape DryWords.aif 0 100 120 ;
G# 9 , tape EnMiTodo.aif 1 100 120 ;
A 10 , tape FuegoRpt1.aif 1 100 120 ;
A# 11 , tape InMe.aif 0 100 120 ;
B 12 , tape InMe2.aif 1 100 120 ;
C 13 , tape FIRE.AIF 1 100 120 ;
C# 14 , tape ASH.AIF 1 100 120 ;
D 15 , tape AiAmorAh.aif 0 100 120 ;
D# 16 , tape NothNorm.aif 0 100 120 ;
E 17 , tape ExtngNorm.AIF 0 100 120 ;
F 18 , tape FORGTN.AIF 1 100 120 ;
F# 19 , tape DeHarQue.wav 1 100 120 ;
G 20 , tape IShlStp.aif 0 100 120 ;
G# 21 , tape RptFirAsh.aif 0 100 120 ;
A 22 , tape silence 0 10 120 ;
A# 23 , tape silence 0 10 120 ;
B 24 , tape silence 0 10 120 ;
This is a spreadsheet used to create the index file for [Transcending Translation], a tape
music piece adapted and arranged for the Airband by the original composer, Laura M
Sinnott. The spreadsheet is a template, which a composer may easily create an edit an
index file. The index file is a txt file with just the cue number thru semicolon on each
line. The tinted area; the header and the reference only note numbers are not to be used
as part of the index file. The syntax for creating an index file from any text editor can be
observed in the header at the top of this spreadsheet. Note that the file name “silence”
actually calls an empty audio file, so that silence can be quickly triggered as a sound cue.
- - 33
for
refe
rence o
nly
Cue N
um
ber
com
ma
tape,
fx, in
str
file
nam
e,
on/o
ff,
instr
num
ber
loop o
n/o
ff,
dela
y1,
tem
po (
if a
pplic.)
xfa
de t
ime, dela
y2
tem
po,
feedback
scale
sem
icolo
n
C 24 , instr 0 ;
C# 25 , instr 1 ;
D 26 , instr 2 ;
D# 27 , instr 3 ;
E 28 , instr 4 ;
F 29 , instr 5 ;
F# 30 , fx 0 ;
G 31 , fx 0 ;
G# 32 , fx 0 ;
A 33 , fx 0 ;
A# 34 , fx 0 ;
B 35 , fx 0 ;
C 36 , fx 1 30 100 0.5 ;
C# 37 , fx 1 176 352 0.5 ;
D 38 , fx 1 500 350 0.2 ;
D# 39 , fx 0 ;
This is a spread sheet of the System cues in TapeJocky. These cues stay the same for
each song. I have reserved the top range of note numbers from [tab.pitchmap] and/or
[tab.4bit++] to for use with instrument switches and effects presets. These controls
could also be included in an index file for a song. The column after the comma is used to
assign and route the rest of the data with each row. The item “tape” sends data to
[lang.dj.xfade2] , “intr” calls the instrument number (0 = all mute, 1 = Lead, 2 = rhythm
guitar, 3 = techno, 4 = rhythmSampler, 5 = shakey-shakey), “fx” sends data to
[lang.pingpongdelay2~] and an associated volume control which acts as a gate. At the
time of this writing System cues 30-35 were not in use, [“fx” 0] is a place holder, which
if called by accident would only close the gate associated with [lang.pingpondelay2~].
- - 34
7.0 Future Work
The musical and technical development for the Airband is on going. On the musical
front we are trying more structured pieces, and attempting to move away from
dependency on the laptop monitor for visual feedback in performance.
The future technical developments include possible wireless communication with the
computer via Bluetooth® technology. There are a few NIME projects, which have
successfully used this protocol to communicate with Max/MSP [Allen 2005, Weinberg
2002, Young 2004]. Also at the time of this writing one of the key performers in the
Airband, Laura M Sinnott, just finished initial development and performed with a
wireless NIME device for use with Max/MSP. Her work was presented as part of the ITP
NIME class concert at Tonic, December 2006. The set up for her performance was to set
a laptop down on stage, plug in the audio and turn on the audio in her patch. She then
started performing. When the Airband played this same show in April 2006, we had to
plug in the MIDI devices plug in the MIDI to USB interfaces, launch Max (wait), load
the patch (wait some more while audio files are buffered in RAM) and start the audio.
This process took probably 2-4 minutes. For a 5 minute performance this was far too
much set up time.
Developments for the Airguitar might include switching to an analog to digital circuit
which is easily reprogrammable, via USB connection from an Apple computer [Arduino,
2006]. This would allow for robust firmware development, such that a circuit could be
switched from Bluetooth mode to MIDI mode. This may be necessary in the event that a
space has too much interference for the Bluetooth connection to work consistently.
The physical device still needs a lot of work. At the time of this writing, the device is
held together mostly with electrical and gaffers tape. The batteries, accelerometers, FSR
leads and even the strap are all fastened with lots of tape. This worked well for a fast
prototype but as time goes on the adhesive on the tape fails. I do not have specific plans
to remedy this at this time, but its something that must be done soon.
The Software offers the most opportunities for fast improvements. During the
preparation for the presentation of this project, several minor improvements took place.
Some of them were documented and replaced older versions of the software maps and
instrument description. Some improvements took place almost in passing and were not
documented. These improvements included parameter adjustments and scaling to
improve sensitivity and range on some of the sensor maps. As they did not represent a
change in the structure of a patch or how it was used, I did not take the time to describe
them. As the Airband develops more pieces and performances, several improvements
will likely take place.
Some improvements that have already been discussed by the performers and composers
in the Airband, include the development of new synthesis routines to use with the
existing mapping routines. For example [tab.nnSynthMap] is general enough that it
could be used to control most any monophonic sustaining synthesizer. [tab.loopSynth]
could be replaced with an oscillator based synthesizer, or a sustaining physical model,
such as a bowed string model [Sarafin, 2004]. The same is true for the [tab.pitchMap] and
[tab.Pulser] mapping routines. They have already been used with two signal generators, a
physical modeling synthesizer and a sample player. Several more synthesis methods are
- - 35
already in the works [Crawford, 2006]. With a larger selection of synthesis methods
using the same control mappings, the performers would not have to learn many more
techniques for playing to have a larger variety of sounds at their fingertips.
8.0 Conclusion
The Airband could potentially perform any piece of electronic music. This could bring
life to many pieces that might otherwise only exist as recordings. There is still work to
be done regarding the technical development of the hardware and software tools used by
the Airband. But with just the existing devices and software tools, tape cue playback
system and a few instruments, a variety of pieces may be played. I hope this text may
encourage others to develop tools for the Airband and/or write music for the Airband, or
ensembles like the Airband.
- - 36
9.0 References
Alford, A, S. Northrup, K. Kawamura, K-W. Chan, and J. Barile. A Music Playing Robot, Proceedings 1999
International Conference on Field and Service Robotics
Allen, Jamie. Boom Box, Proceedings of the 2005 conference on New interfaces for musical expression
Arduino 2006 http://www.arduino.cc/
Cook, Perry Principles for designing computer music controllers, Proceedings of the 2001 conference on New
interfaces for musical expression.
Chadabe, Joel. Devices I Have Known and Loved. In Trends in Gestural Control of Music. M.M. Wanderley and M.
Mattier, eds. Ircam – Centre Pompidou. 2000
Chadabe, Joel. Electric Sound: The Past and Promise of Electronic Music 1997
Chadabe, Joel. Solo: A Specific Example of Realtime Performance in Computer Music – Report on an International
Project. Canadian Commission for UNESCO, Ottawa, 1980.
Chadabe, Joel. The limitations of mapping as a structural descriptive in electronic instruments Proceedings of the 2002
conference on New interfaces for musical expression
Collins, Nick. "Generative Music and Laptop Performance." Contemporary Music Review 22/4, pp. 67-79, 2003.
Crawford, L. String Madness Final Paper for Digital Signal Theory @ NYU fall 2006
Cycling 74 Manual and Help files downloaded from company webpage 2006 http://www.cycling74.com
Didkovsky, N., L. Crawford. Java Music Specification Language and Max/MSP Proceedings of the 2006 International
Computer Music Conference
Mann, Steve personal webpage 2006 http://wearcam.org/septambi/
Microchip 2006 http://www.microchip.com/
Moog Music manual downloaded from company webpage 2006 www.moogmusic.com/manuals/ewave_user.pdf
Raskin, Jeff. The Humane Interface: New Directions for Designing Interactive Systems Addison Wesley 2000
Rokeby, David personal webpage 2006 http://homepage.mac.com/davidrokeby/softVNS.html
Rovan, J., Wanderley, M., Dubnov, S., and Depalle, P., Instrumental gestural mapping strategies asexpressivity
determinants in computer music performance in Proceedings of the Kansei – The Technology of Emotion Workshop
1997.
Serafin, S. The sound of friction: real-time models, playability and musical applications. PhD thesis, Stanford
University, Stanford, CA, 2004.
Smith, J.O. Physical Audio Signal Processing, 2006 http://ccrma.stanford.edu/~jos/pasp/
Sonami, Laetitia personal webpage as of 2006 http://www.sonami.net/lady_glove2.htm
Sturman D, Zeltzer D. A survey of glove-based input. IEEE computer graphics and applications. 1994.
Waisvisz, Michel personal webpage 2006 http://www.crackle.org/TheHands.htm
Wanderley, M. and M. Battier, 2000. Trends in Gestural Control of Music. (Edition électronique.) Paris: IRCAM.
Weinberg, G., Aimi R., Jennings, K., The Beatbug network: a rhythmic system for interdependent group collaboration,
Proceedings of the 2002 conference on New interfaces for musical expression.
Wikipedia 2006 http://en.wikipedia.org/wiki/Comb_filter
Also: /Data_glove , /Karplus-Strong_string_synthesis, /Keyer , /Theremin , /Doctor_Who, /Air_guitar, /quasimode
Young, D., Fujinaga,I., Aobachi: a new interface for Japanese drumming, Proceedings of the 2004 conference on New
interfaces for musical expression.
- - 37
