Triads Within Tonality -

Tonality may be defined as the supremacy of one particular tone which lies at the center of a harmonic or melodic texture.

A Primary Tendency is a strong attraction between scale degrees. The second, fourth, and sixth scale degrees have a strong tendency to resolve into the first, third, and fifth scale degrees, respectively, and the seventh scale degree has a strong tendency to resolve upward to the eight scale degree.

A secondary tendency is a week attraction between scale degrees. Primary and secondary tendencies are illustrated in example 10-a

Example 10-a

Only a small number of melodies would be possible if composers resolved all tendency tones immediately. The immense variety of melodies found in music literature has resulted from the composer's prerogative to delay some resolution of tendency tones and to avoid resolution of other tendency tones. Example 10-b illustrates both immediate and delayed resolution of primary and secondary tendency tones.

Example 10-b

The word "diatonic" means moving by step or half step. When the term is applied to triads, diatonic denotes those trials which are drawn from a scale. The diatonic triads which occur in major tonality are of the following names and types.

Example 10-c

The dominant is perfect fifth above the tonic, the sub dominant is a perfect fifth below the tonic. The mediant is the diatonic third between the tonic and the dominant: the sub-mediant is a diatonic third between the tonic and the sub-dominant below the tonic.

Example 10-d