The way things are going these days at the Kennedy Center, I wouldn't be surprised if they installed water slides on the roof terrace and a Tilt-a-Whirl in the basement.

And why not? After all, the Opera House of what claims to be the nation's foremost cultural center is already housing "Satchmo," a musical that at its best moments is on a par with the revues you get at Kings Dominion. And Saturday night, "Shear Madness," a participatory cabaret entertainment-cum-murder mystery, opened in the Theater Lab. In neither case is the center aiming high.

I'm not sure the center is aiming at all -- just scrambling madly to rope in the customers and fill up the halls. Art -- or at least art as Peter Sellars practiced it -- proved box office poison. Now the pendulum has swung. This is the summer of glitz, blare and faggot jokes at the center. A body could despair.

"Shear Madness" has already chalked up long runs in Boston, Chicago and Philadelphia, which says something about popular taste, or the lack of it. In the proper setting, an intimate cafe'-theater, and with actors who didn't cram the hilarity down an audience's throat as if they were force-feeding a flock of geese, I suppose it might prove mildly diverting. I am told by one who caught the show early in the Boston run that it was quite funny, although he was definitely not clutching his sides Saturday night.

I can only report that "Shear Madness," as it has been reconstituted here, struck me as being as appropriate as a pie-eating contest on the White House lawn, and somewhat less amusing. Adapted from a Swiss play by Paul Portner, it invites the audience to investigate a crime that occurs midway through the first act, interrogate the witnesses and then vote for the guilty party.

It works like this: We are in the lemon-yellow Shear Madness Unisex Hairstyling Salon in Georgetown. Its proprietor, Tony Whitcomb (Bruce Jordan), has had a long-running feud with his landlady, a reclusive concert pianist who lives upstairs. For the first 30 minutes, the emphasis is on broad farce, as Tony and his peroxided assistant Barbara (Robin Baxter) service the day's clients and try to overlook the thunderous bursts of piano music from above. Then there is a piercing offstage shriek and the cops are at the door.

The pianist has been murdered with a pair of scissors and everyone in the shop -- which includes a pasty-faced antiques dealer (Michael Gabel) and a society snoot (Marilyn Abrams) -- is under suspicion. That's where the audience comes into the picture. According to instructions from one of D.C.'s finest, Tom O'Brien (Matt Callahan), the events we have just witnessed will be reenacted. If, however, we catch any of the suspects lying or engaging in a cover-up, we are urged to call them on it right away.

There's more. After intermission, the audience can actually grill the suspects firsthand, make them wriggle and squirm, catch them in a contradiction. Or attempt to. As participatory theater goes, this is much more satisfactory than the 1960s version, which sought to coax audiences into shedding their clothes or taking to the streets in a state of antiwar dudgeon. Indeed, if Alan Ayckbourn had written the script and the performers were of Second City caliber, "Shear Madness" might just live up to its title.

Nothing, however, turns out to be half so clever as the evening's premise. Jordan (who is responsible for the adaptation as well) makes a point of setting the show in the town it's playing and lacing the script with local references. Hence, his squeal as the flighty hairdresser: "I get two blocks off P Street and I'm lost." The undercover cop lives "out in the country." Asked where, he explains, "Hyattsville."

There are jokes about Amtrak, Bartles & Jaymes, Vanna White, Joel Hyatt and Tony's cats, "Little Ollie and Fawn." Under sharp questioning from the police, the snooty socialite replies, "I think I'll stand on the Fifth Commandment." Her name is Mrs. Shubert, but the cops call her "Mrs. Shoebox." A lesbian relationship is referred to as "a Lebanese relationship." The antiques dealer, given directions to the men's room, is told, "You can't miss it." "I'll try not to," he retorts with a snigger.

It takes skilled actors to pull off low humor, and this cast is laboring under a decided handicap -- frantic, overemphatic, no-holds-barred direction (that's Jordan's fine hand again). Only two performers manage to suggest a talent greater than the shrill circumstances demand. Robin Baxter, as the brassy assistant, is as sharp as an emery board -- a Judy Holliday who's long since learned to look out for her own interests. Nice work, too, from Gabel, who qualifies his shifty demeanor with sag-eyed expressions of innocence and incredulity when the guilty finger points his way.

Otherwise, the show seems beamed at audiences seated somewhere in Rosslyn, with the red-faced Jordan hissing and screaming every step of the way. Curious that such a flagrantly outrageous depiction of homosexuality passes for humor these days. If, say, a black, a Jew or a Catholic were depicted in such stereotypical terms, there would be all hell to pay.

But what can you say about a show in which one character, identifying the music filtering down from above, says, "Rachmaninoff," and another immediately replies, "Gesundheit!"?

I, for one, say, "Spare me."

Shear Madness, by Paul Portner. Adapted by Bruce Jordan and Marilyn Abrams. Directed by Jordan. Lighting, Daniel MacLean Wagner; set, adapted by Peter Kim Kovac. With Marilyn Abrams, Robin Baxter, Matt Callahan, Michael Gabel, Bruce Jordan, Steve O'Connor. At the Kennedy Center Theater Lab for an open-ended run.