ON THE TOWN: L.A.'s rock fraternity turned out in droves at the Roxy Monday night at a star-studded benefit for ailing club booker Michele Myer. The all-night extravaganza was hosted by KROQ's Rodney Bingenheimer and actor Ed Begley Jr., who introduced Michael Des Barres' band with: "I knew this guy even before Silverhead." Highlights included a raucous reunion of the Knack, a blast of hot guitar licks from Dweezil Zappa (when is someone going to sign that kid up?), a bluesy harmonica solo by "Moonlighting's" Bruce Willis and an exuberant wee-hours jam session featuring ex-Sex Pistol Steve Jones, Charlie Sexton, ex-Duranie Andy Taylor, Motley Crue's Tommy Lee, Des Barres, Zappa and ex-Go-Go Charlotte Caffey. Many of the kudos go to Des Barres, who helped organize the event and put on a stellar show himself, crooning a fiery rendition of Don Johnson's hit, "Heartbeat," and joining the Crue's Vince Neil in a pair of rave-up versions of "Jailhouse Rock" and "Rip It Up." Asked what she thought of the noisy proceedings, Myer said, "This was so much fun, I don't know why we can't do it every night of the week!"