I was getting into some music on the commute home the other day, lamenting the fact that I don't have a drum set to practice on anymore when I was struck with this business idea. Rent a smaller stand-alone building and renovate it to have reasonably sound-proof practice rooms. Furnish smaller rooms with drum kits, leave some empty (for electric guitar/bagpipe/tuba practice), and make some bigger for bands to jam in.
Many drummers, musicians in general have no where to practice in cities because it disturbs the peace. Renting these practice/jam rooms out might be an interesting and franchise-able business opportunity. My wife could only listen to me play the piano at home for so long (and I don't think I'm that bad - 11 years Royal Conservatory). As soon as I started practicing technique, her patience got thin. :-)