After talking about the Shepard Tone, an audio illusion that can create an endlessly rising or falling scale, with my friend Ben Pender, I decided to try to create one using Lilypond. The result is quite interesting.
Chromatically rising Shepard Tone:
The midi file created by Lilypond: shepard_tone.midi
A wav file generated from the midi file above: shepard_tone.wav (43M)
An mp3 file generated from the wav file above: