Give First Avenue credit for balls: Their dance nights have been pared down, with the V.I.P. room temporarily closed, and regular Mainroom dance hours reduced to Thursdays, Fridays, and Saturdays (with a 21+ age restriction all three nights). But instead of establishing a surefire cheesy dance format (more '80s hits, anyone?), the big black bus station has let passionate DJs cater to specialized audiences since the change of ownership and brief closing last November. The results have been good for music: Saturday's electro-dance night BA-SIK (along with Tuesdays at Mell's Beauty Bar and Fridays at the Dinkytowner) is a refuge for the post-rave set, with national acts ranging from Chicago house hero Felix Da Housecat to Canadian techno innovator Echoplex, and with local DJ E-Tones spinning regularly in the meantime. Fridays belong to the Energy Lab, a hip-hop/R&B/dancehall night hosted by Verb X with guest DJs including L.A.'s Kamikaze. Thursdays are the club's longest-running success, Ritmo Caliente, which features salsa, cumbia, and reggaetón spun by DJ Tony, along with dance contests for cash prizes and informal dance lessons. The sound system is among the best in the city--no small consideration, particularly for salsa. But these nights have something else going for them--cheap (often free) crossover to see live bands in the 7th St. Entry next door. For those who want rock and roll in their salsa, rap, and techno, First Avenue still beats its rich competitors on a shoestring.