The winner above is great and all, but they aren't really a music store, per se. They should really be in the "Best Record Store" category if you ask me. The best music store in Houston is MusicWise on Richmond and Shepherd (2131 Richmond Ave, to be exact). They specialize in vintage guitars and keyboards as well as modern recording gear, which is what a music store really is. The owners are super knowledgable and helpful, too. My vote for Best Music Store is MusicWise!
Best Music Store Houston 2007 - Sound Exchange
This Montrose-area establishment has been supplying local music snobs with the most epicurean of sounds for years now. No matter if you're looking for the latest vinyl release from an obscure noise band or a self-manufactured CD by a local group, Sound Exchange is the place you're most likely to dig it up. By no means does this little house-turned-record-store have the largest selection in town — they just have one of the finest. The employee-recommended picks are a guaranteed way to learn about new music ahead of the curve, and the well-priced used vinyl makes this place hard to leave without happily spending some cash.