You can name a band anything you want, of course; but the last group of jazz singers to use a name out of the legal directory was Lambert, Hendricks & Ross, and I’ve got to think the similarity is intentional. In any case, Sharon Montgomery, Rebecca Plant, and Billy Stritch (who also plays a lot of piano) have themselves one solid and versatile trio: they jam a little, scat a little, and manage to make those three-part harmonies sound surprisingly fat. In years to come, they might carve a place in the jazz-vocal history, but their appeal is not restricted to wiggy aficionados: in addition to Basie’s loping “Shiny Stockings” and a gorgeous ballad from the Woody Herman book, their set includes a Patsy Cline torcher and reaches some sort of peak with a 29-song Irving Berlin medley. It’s all done up with the kind of bright musical sophistication and Broadway energy you’d naturally expect from a clever New York cabaret trio–which makes the fact they’re still based in their native Houston all the more surprising. Tonight through Sunday, Moulin Rouge, Fairmont Hotel, Illinois Center, 200 N. Columbus; 565-7440.