Hi guys, I don't mean to discredit what KillerQuebec said by any means, but I probably will anyways. There is a 0% chance that you will ever get any kind of "other duty" if you are enlisted as a musician.
False.
Only the "special" band programs are exempt and even with that the pentagon can change policy any time they want. If you enlist in any non special band program, you can easily find yourself doing non-music duty.
I spent 3 years in the army field band in Ft Meade MD, a special band unit so I know what I'm talking about.