Madwaves made the madplayer (now discontinued). Now they’re making a software version called madmixer.
And, you ask?
Well, the hardware version (madplayer) wasn’t that bad at all. In fact it was quite handy to use if you were short of a little musical inspiration. It generated music using algorithms in different styles.
That’s what the “madmixer” application will do too. However, they’re porting it to Java so it may run on a Treo. If it does I may well try out a copy and see if it is worthwhile.