PiData, by Cyborg K aka David A. Powers. All synthesis and sequencing was done by a single Pure Data patch, rendered in a single take, then normalized in an external sound editor. More complex synthesis and fx were done with the aid of the Pure Data [vst~] object. The custom [getpi] abstraction was used to output n digits of the first 10,000 digits of Pi at a time: all variable parameters, whether harmonic, rhythmic, or synthetic were driven by instances of the [getpi] abstraction. Overall rhythmic structure was based on the fibonacci sequence: 8 + 13 + 21 + 34 + 21 + 13 + 8 + 34 + 21 + 13 + 8 = 194 seconds = 3:14. The piece took about 15-20 hours to complete, including building abstractions from scratch within Pure Data.
Link: http://www.cyborgk.com/audio/cyborgk-pi_data.mp3
*PS. This is the first time I have composed an entire piece in the Pure Data environment...
~David