JOAN MAY BE GONE, BUT ‘LATE’ ROCKS ON

Dressed in black leather and chain metal from head to toe, the Cult’s lead singer, Ian Astbury, warily eyed the crowd of guests and visitors in the Green Room at the Fox Network’s TV studios in Hollywood, former home of “The Late Show Starring Joan Rivers.”

In one corner was actress Rita Moreno, surrounded by a crowd of friends. Across the room was Mother Angelica, a Birmingham, Ala., nun who was out touting her new book, “Answers, Not Promises.”

“Geez,” Astbury said as he grabbed beer from the bar. “We’ve done some strange shows, but American TV--it’s just weird!”

Weird sounds just about right. Since “The Late Show” debuted last October, it has been plagued by horrible ratings, critical snubs and internal uproar. Matters came to a head May 14, when Fox abruptly gave Rivers the ax just hours before the Cult appeared on camera to destroy most of their instruments and (rented) equipment during an anarchic remake of “Born to Be Wild.”

However, while Rivers has been relegated to occasional guest-host status, the show itself remains intact, in particular its adventuresome music policy. In fact, for the past six months, “The Late Show” has been an unlikely oasis for wild ‘n’ crazy rock groups, spotlighting such raucous talents as the Beastie Boys, Husker Du, Wendy O. Williams and the Psychedelic Furs.

It’s no secret why the show has courted such a fresh coterie of pop up ‘n’ comers, some so obscure that they can get booked on “The Late Show” but can’t get played on KROQ-FM. Fox execs say that the program’s major strength has been with 18-to-35-year-old viewers, who are eager to stay abreast of the latest pop developments.

“We have had some pretty wild booking combinations,” acknowledged talent exec Patty Bourgeois. “The other night, we had the Psychedelic Furs and Betty Ford. We really get a kick out of having these odd couples. From the start, the whole idea was to think of this show as a buffet--and let me tell you, we’ve had some really unusual buffets.”

Unlike other talk-fests, “The Late Show” has given most bands the opportunity to sit and chat with the host after they’ve finished performing. When the show’s bookers discovered it was Astbury’s birthday, they treated him to a surprise, on-camera phone call from his dad, who offered his greetings from Canada.

But half the fun was watching the backstage dressing-room interplay between the band and its pals, who on this visit included Cult producer (and Run-D.M.C. rap mastermind) Rick Rubin. With time to kill, the band sampled milkshakes and fast-food sandwiches while Rubin set up and canceled appointments on the phone.

The group also commandeered a video machine so they could pick a director for the group’s next clip. Watching the first clip, Bon Jovi’s “Wanted Dead or Alive,” guitarist Billy Duffy told Rubin: “We should really have a girl in the next video, you know.” Rubin wagged his head. “No way! You don’t want a guy who’s having some relationship with a girl. You should just have the guy--and lots of girls, everywhere!”

The next clip was a new video by the Cutting Crew. “Boring!” the band said in unison, after about 15 seconds. “Next!”

By the third clip, the group seemed weary of all this complicated auditioning. Informed that Wayne Isham’s video firm--the same company who did Bon Jovi’s video--had produced the clip, the group seemed satisfied. “Well then, they’re the ones, aren’t they,” Duffy said with finality. “That’s decided. Let’s go.”

And with that, the band trooped off to a rehearsal, leaving the Fox offices spattered with a trail of spilled strawberry milk shakes. “You know,” Duffy amiably explained to one of the group’s road crew as he held up a crumpled milkshake container, “these work a lot better with the top on instead of in the bag.”