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.

Also in this directory are scans on the original user manual and 
function key strips.

I've included high and low resolution scans.

Happy music making!