I have bad luck buying CDs. I hear a band on the radio or download a track through Napster, fall in love, and rush out to buy the record. My discoveries, unfortunately, usually turn out to be the work of one-hit wonders and end up under the front seat of the car with the empties and ketchup packets within a week. But there are a few sure musical bets. If Greil Marcus writes a positive review of a record, I know I’ll like it. The same goes for whenever Rob Crow has a new band. From the avant-instrumental Physics to the quirky Heavy Vegetable, from the toy-organ-driven Optiganally Yours to the amazing Pinback, Crow has never let me down. Whatever group, whatever album, his dreamy guitar work, intriguing lyrics, and sly sense of humor always create songs that are simultaneously grand and delicate. So when his latest project, Thingy, plays tonight, be sure to buy a copy of its new CD, because there’s no such thing as bad luck with Rob Crow around. With John Sinclair at 10 p.m. at the Velvet Lounge, 915 U St. NW. $5. (202) 462-7625. (Lisa Locker)