Composing Music by William Russo: Chapter 16 (part 2)
Russo uses the term Kaleidoscopic Ostinatos to refer to two or more ostinatos of differing lengths that occur simultaneously.
For this next exercise, I created an accompaniment with four ostinao patterns of different lengths:
Pattern a is three beats long, repeated 20 times.
Pattern b is two beats long, repeated 30 times.
Pattern c is 4 beats long, repeated 15 times.
Pattern d is 5 beats long, repeated 12 times.
These four patterns converge every 15 measures. I dutifully stuck to the script for the first fifteen measures, and then I jumped over the fence. For simplicity's sake, the melody, all additional layers, and the accompaniment after m.15 are not notated in the abridged score below.