Update: And here's my first attempt at melody by division:
2, 3, and 5 are like the opponent-process dimensions in color. The aesthetic rule may be similar, requiring some but not too much variation in each dimension. More on this to come.
Oh yes indeed.
By changing the amount of variation desired, different effects can be achieved.
This last one composed by my computer while I read Stross's latest Laundy story.
Further tweaking:
The main thing currently lacking is a feeling of progression.