BooTracker is a simple, yet powerful music tracking program. Written by Simon Forrester (aka Boo The Ghost), it appeared on Amstrad Action covertape No.26.
The software enables you to track your own music, using either ready-made instruments, or you could make your own in the instrument editor. You have 3 channels to work with. The finished arrangements can be saved as a .mus file, which will play back using an interrupt, so you can incorporate them in your own programs.
BooTracker used firmware sound routines, rather than directly addressing the PSG, so was unsuitable for demo or more advanced game use. Nonetheless, it was capable of very good results, not least because of the firmware's 100Hz sound-generating frequency. Perhaps the most impressive product of BooTracker was the 'Jean-Michel Jarre Demo Disque' by SWiB of The Underground.