I decided to go back to an old tool for this Junto: Scape. This is a graphical composing program which runs on the iPad, and which lets you assemble generative scenes -- "scapes" -- from a large set of graphics with attached sounds and behavior. You can then create playlists that move from scene to scene, with control over how long a given scene plays and how long it takes for old objects to be removed and new ones added, but the objects themselves do what they do.
Because the individual parts interact with one another, and the parts behave differently at different times, the results are predictable only within certain limits, and the process of "composing" with Scape is primarily intuitive.
I chose to start with some relatively static textures, build them up to something much thicker and noisier, and then taper off into a more melodic texture. The initial version was okay, but not perfect; I then decided to split the track at the point I switched over to the melodic texture and combine it with the first, noisy part. The result was very satisfying and is the final track.
