Mobile/Auto Instruments!

I very much like the instruments in the game, but I often run into the problem that I constantly need to switch to a sword or something so I don't die. And some of the music I find sounds adventurous, so I'd like to bring it along with me. What I want seems fairly simple, the ability to select a song from an instrument and stay in the background while I select other things. Maybe some sort of 'auto' modification can be made or something, or 'miniature' versions you can play on the go with ease.