By Shirley Halperin
February 07, 2007 at 10:11 PM EST

The one thing I love about L.A.’s Cahuenga Crawl — what we call that one block between Hollywood and Sunset Boulevards, which houses at least five highly frequented bars — is that you never know who may be inside any one of those joints. Like last night: As countless hipsters hopped between the Burgundy Room and Beauty Bar, I’m sure many didn’t realize that at the 200-person capacity Hotel Café right across the street, Rage Against the Machine’s Tom Morello (pictured) was not only performing the final L.A. show of his residency with Nightwatchman, the solo acoustic outfit that’s been taking up much of his time of late (when he’s not mentally preparing for Rage’s upcoming Coachella performance), but also hosting a multi-artist bill and leading an all-star sing-along. Walking by, someone could have mistaken it for karaoke night, but despite the occasionally drunken-bum note, it was far from amateur hour.

This evening started out mellow, with sets by Morello, Jill Sobule, Shooter Jennings (with Velvet Revolver’s Dave Kushner), and Ben Harper offering covers (Jennings impressed on Patsy Cline’s “I Fall to Pieces”) and new originals (Harper introduced “Lifeline,” the title track from his forthcoming album), but it was full-on rocking for the finale, which featured the four performers joined by several friends on a very small stage. Cheering on the all-star jam, which included renditions of U2’s “Vertigo” and Bruce Springsteen’s “Born in the USA,” were actresses Drea DeMatteo and Winona Ryder as well as Tom Morello’s mom, Mary, whom he affectionately name-checked from the stage by shouting, “Everyone except my mother, stand the f— up!”

addCredit(“Tom Morello: Sean Ricigliano”)

What was deserving of a standing ovation? A surprise appearance byCypress Hill’s B Real and Sen Dog, who immediately launched into theirbiggest hit, “Rock Superstar,” backed by Morello on guitar; certainly Iwasn’t the only one who felt a ’90s flashback coming on (visions of LimpBizkit be damned!). The time warp continued with the stoner anthem“Insane in the Brain” and 2Pac’s “California Love,” which, notsurprisingly, garnered resounding applause.

“I’ve done seven of these already and they’re a lot of work,”Morello told us after the show. “I’m basically booking them myself.”But despite “a hiatus” inL.A., Morello hinted that he may take the residency to the East Coast — sokeep an ear out, Boston, New York, and D.C.