Actually, it is 100% perfectly acceptable and safe to use Control^C for this. What it does is tell the player that you want it to quit. If the player knows how to deal with this, it quits. If it doesn't know how to deal with it, then Linux forces it to terminate. Either way, all files get closed, and life goes on.

And since the Empeg's filesystems are R/O, there's no danger to the music data. The other hidden partitions may be getting updated at the time, but damage is extremely unlikely or even impossible here -- consider that it's all designed to lose power at any possible moment. Hitting Control^C for a more controlled shutdown is innocuous by comparism.

Cheers