I could totally see them making a furniture store, with all the creative ways they've made furniture over the years, and small furniture pieces uses a lot of small pieces, which seems to be the Lego M.O. these days.
The only problem with it is, how do you fit all the furniture into a small space, a space made even smaller by a potential music shop.
Here's an idea... what if it were a furniture shop, meaning a furniture workshop that built furniture? Then you wouldn't need all kinds of furniture pieces; you could just have a few that the carpenter was working on at the time.