Interval Analysis

February 22, 2009 Ideas 0 Comments

In order to make a better progression module that retains both originality and coherence, I need a method for evaluating certain qualities of progressions. One can break progressions into individual chords for easier analysis. Even better, one can break chords down into intervals for the most specific analysis. Intervals, which are more specific than individual notes, yet more general than chords, provide a good basis upon which to judge qualities of chords and progressions with fair accuracy.

I made up three criteria for intervals and evaluated every interval in the minor key based on the criteria (which have values between one a five, inclusive). Higher mood values indicate a 'happier' feel while low mood values indicate a 'somber' feel. High suspense values indicate a sense of tension in the interval, while low values designate chords with greater stability. Low consonance values indicate a clashing of harmonics, which high values indicate a relatively consonant interval.

Below is the table of intervals and quality values I wrote down. 'Bad' intervals, or those with a consonance value of 1 have been marked in red.

Interval: Mood, Suspense, Consonance
1-2: 1,5,2
1-3: 2,2,5
1-4: 2,3,4
1-5: 3,4,4
1-6: 2,4,4
1-7: 2,3,2

2-3: 1,4,1
2-4: 3,2,3
2-5: 2,3,3
2-6: 2,5,1
2-7: 4,2,4

3-4: 3,4,2
3-5: 4,2,4
3-6: 5,1,5
3-7: 5,2,4

4-5: 3,4,2
4-6: 3,3,3
4-7: 4,3,3

5-6: 3,4,1
5-7: 4,2,4

6-7: 4,4,1