Just some clarifications:
– CodeSounding is open source (GPLv3) – see http://sourceforge.net/projects/codesounding/#more. Official source and binary releases include its text
– CodeSounding sonifies the Java instructions, as they are triggered at runtime: so not the static source structure.
– The sorting example is just a “standard exercise”; you can also sonify a multi-threaded Swing application – see for example http://www.youtube.com/watch?v=2J662O16f7E

The major challenges are 1) keeping realtime synchronization between instructions executed and sounds played, 2) how to “compress” the CPU speed into a meaningful rhythm, that is how to going from 2GHz to 44kHz.
Of course, getting good audio samples is a hard work, and would well require a musician 🙂

Finally, let me signal you the following links, I hope you’ll enjoy them:
– data sonification is used at NASA as well, when analyzing space data: http://spdf.gsfc.nasa.gov/research/sonification/sonification.html
– the “Institute for Algorhythmics” (http://www.algorhythmics.net/en/?p=427) sets a conceptual framework for these experiments