By doing a little spy work I was able to take some photos of my friend's "band room" without him knowing it. Then when I printed the photos I just used the Kodak machine at the store to make a preset collage. It was super easy and only took about ten minutes. You don't even have to make the collage yourself, you can keep hitting the "shuffle" button until the photos are in an order that you like. I think the most important thing is to take close up photos of several details of the hobby. Total cost for frame and all $7! Can't beat that.
I think he is going to be very surprised and excited about this gift.