Hi all and Tom,  You can pick up one of those home type Karaoke
sound systems, usually at a yard sale, flea market or a thrift shop for
sometimes under $25.00 and they work just fine.  Usually they may even
have two mics.  So you could use one mic for the music box and one mic
for your own use.

Sometimes schools have available audio systems from their audio visual
department you could use.  Ask the school and see what they might have.
Good luck!

Musically,
Larry Norman - Lots of rain today, but the trees and flowers are in
full bloom.  A great time to enjoy the Beautiful Blue Ridge Mountains
and the rest of Virginia.