"Mutator OD Bass" [1.9 MB .mp3]. The Mutator is an analog filter unit with a very full, liquid sound. It is practically a synth unto itself. This piece uses a couple of repeating bass notes that are transformed by external audio and MIDI signals affecting the Mutator's LFOs and envelope followers. The drums are the only thing added, the rest is the Mutator and mostly done in real time.
(reposted with additional info.)