In the source code that I have provided for the sigma-delta part of the DSP core that I am working with on the Parallax P1, I have discovered that if I do some extreme underclocking when I simulate the Analog to Digital conversion and subsequent filtering using the Song "White Wedding" by Billy Idol as a test, well it seems to add an interesting what should I call it - but maybe it is a sort of "don't forget to bring the rice" like sound effect to the music, let's say around 4 minutes or so into the song;  or else it sounds almost like adding a maraca to the existing track - playing in perfect lock step to the beat!   This could of course lead to an extremely simple beat detection hack, which combined with a polyphase filter tree and some event detection hysteresis!