I updated the license from PFL and BSD of my synth-sampler program to GNU's GPL 3, you can find the updated files here :

https://sourceforge.net/projects/pyxiesynth/

pyxiesynth is a program which reads and parses bitstreams from a sound file and then rewrites them back to disk. You can alter the music by shifting and counting bits in an 8-bit packet of audio file (I do not mean the library) then mixing samples from different sources. HTH, enjoy!