I am building a series of squelchy, tree-dwelling analog synths called 'songbirds.' Here's a picture of the prototype, whom I've nicknamed Tyagaraja, after the 18th century Karnatak composer. Songbirds are designed to react to ambient conditions. Tyagaraja responds to changes in light, because photocells are simple and cheap (at least, for now). He consists of a synth element, which can be calibrated using four knobs, an array of resonators (made from coffee cans), and a speaker. He runs on batteries. Future iterations will consider alternative sources of power- they don't need much current at all. The synth element has two audio-rate oscillators, two low-frequency oscillators, and several filters.
Schematics and longer sound examples will follow deployment next weekend. Here's a close-up of his synth element:
The textures he produces vary with the time of day. Here's a short sample of one of the textures he's capable of making at night: