Here is Island Logic's Music System for the BBC Micro.

MusicSys.zip contains MusicSys.ssd which is a single sided 80 track image version of the main system disc. The protection was removed from the original floppy purchased way back in the 80s by Kieran Mockford.

The other .zips contain various sample music files from some of the PD libraries floating around the web.

I haven't been able to locate scans of the manual on the web, however I do have it and will be scanning it and the accompanying function key strip as soon as I get a chance.

Happy music making!