TUESDAY >> The Black Cat’s making good use of its Backstage this week. Before you go check out the Alphabetical Order tonight, read DCist’s interview with the band and see where their heads were about a year ago. Any band that gives their site a dot-org domain is worth at least a cursory glance. With Omega Band, $5, 9 p.m. >> If you buy your music at Starbucks, you may be one of the many…