Rest easy. There exist Mac emulator applications, to re-run OS9 on an OS10 (sorry, OS X) Mac.
Find out more about Mac emulator software here:
https://macintoshgarden.org/macintosh-garden-guides
Find OS9 Music and Sound aplications here:
https://macintoshgarden.org/apps/music-sound
For futher info. & tips on hardware, see:
http://macos9lives.com/mac%20os%209%20lives_002.htm
Plus ça change...
