Quantitative Analysis of Phrasing Strategies in Expressive Performance:
Authors: Eric Cheng and Elaine Chew Year: 2008
Presentation by: Elvira Burdiel GalendeELEM021, Queen Mary University
19 March 2012
Computational Methods and Analysis of Performances of Unaccompanied Bach for Solo Violin
Introduction 1/2 Goal – Quantitative analysis of
phrasing strategies of expressive performance in violin. Andante movement from Bach’s Sonata
No.2 in A minor BWV 1003 for solo violin Regular pulse Unambiguous phrase structure
11 recorded performances + average Unlimited musician freedom on
expressive performance?
Introduction 2/2 Look for indicator of phrasing strategy:
Tempo extraction Loudness/dynamics extraction
Analysis of phrasing strategies via LMPD method Phrase strength - clarity Phrase volatility – variability of strength Phrase typicality – uniqueness of strategy
Tempo extraction Violin: soft indetermined onsets
No reliable and accurate automatic beat tracking tool
Manual onset detection using a digital waveform editor. Tempo = inverse of inter-onset interval Rectangular smoothing window
Dynamics extraction Use two existing models:
1- Single-band Leq (RLB) model 2- Multiband PEAQ loudness model Sample loudness at onsets Smooth by Gaussian window
Test models with manual annotation Correlation higher on 2 -> method
chosen
Extracted data Global means and ranges Section means and ranges
4 sections: A A’ B B’ Phrase means and ranges
Extracted data - global
Extract data – Section means
Extract data – Section ranges
Extract data – Phrase means
Extract data – Phrase
Data extraction - Phrasing
Loudness -> more consistent
LMPD Method Local maximum on loudness per
phrase Phrase strength (clarity)
Difference between max and adjacent mins Phrase volatility
Standard deviation of strength over performance
Phrase typicality (uniqueness) Popularity of location of max
LMPD results 1/2
LMPD results 2/2
LMPD Conclusions Finite number of local maxima counts Phrase strength and volatility relates
to listening perception Typicality (uniqueness) vs greatness
of performance
General conclusions Significant differences between
tempo and dynamics consistency with phrasing strategy
Different constraints of tempo and dynamics, different perceptions
Dynamics more consistent in this analysis, opposite on other studies
Cultural constructs