Once they let the Stray Cats out of the bag last weekend at the Orpheum, there was no holding them back. Performing to a packed crowd, their act was propulsive, zestful, even stunningly athletic. (Lee Rocker played stand-up bass from a variety of challenging positions, even once with his instrument held over his head.)
While the amplification overpowered and clouded some of the Cats' strengths - lead singer/guitarist Brian Setzer's classy voice for example - they won over their awed audience. The Cats lit off their rockabilly hits - ''Rock This Town, '' ''Stray Cat Strut,'' and others - like fireworks, though nuance was often lost in the fervor of presentation.
Special credit should go to the doo-wop group Fourteen Karat Soul for their superb opening act.