If that’s got you in stitches—an eternity of checks = plaid forever, get it?—this lighthearted, lightweight celebration of close-harmony singing is a must-see. If, however, you insist on a modicum of sophistication in your musical humor, you might want to give Forever Plaid a pass. Noel Coward it’s not.

It is, however, kinda fun. The Marquee is cozily intimate, the four plaid-clad performers are surprisingly talented, and the whole shebang is charming without ever crossing that deadly line into cutesy. Check cynicism at the door, invite your mother (she’ll love it) and your Aunt Louellen, and go for the great tunes. When, after all, did you last hear “Papa Loves Mambo?” Or Sonny Skylar’s rollicking tongue-twister, “Gotta Be This or That”?

Stuart Ross’ script tells us that the Plaids were high-school buddies, four fresh-scrubbed young products of the Eisenhower era who, inspired by guy groups like the Four Freshmen and the Hi-Los, believed pop stardom was just an Eb-diminished doo-wah away. Sadly, their promising career was cut short when, as they drove to a breakthrough gig at an airport hotel lounge, a school bus carrying a cargo of Catholic schoolgirls to a Beatles concert smashed into their cherry-red 1957 Mercury convertible. (“Snuffed out by a busload of parochial virgins,” laments one Plaid, in the nearest thing the evening offers to ribald humor.)

Through some miracle of harmonic convergence, however, the Plaids have been given the chance to return to the temporal realm for a single concert—which of course the audience has just happened to stumble into. If all this seems a trifle labored, that’s because it is; Ross’ book is the lamest bit of writing this side of a UPN sitcom. It barely establishes characterizations for the four Plaids, and dialogue consists chiefly of feeble jokes on the order of, “I’m rolling over in my grave right now,” and “We’re gonna have the biggest comeback since Lazarus.”

But the script isn’t the point of the evening, of course; Forever Plaid is about fabulously bouncy tunes like “Crazy ‘Bout Ya Baby” and campy readings of dated heartbreak gems like “Perfidia.” It’s about four guys who put their hearts into swoony confections like “Moments to Remember” and “Shangri-La,” and who aren’t afraid to look ridiculous when the director asks one of them to stick his lips through the hole in the center of a 45 or make clanking noises on a ketchup bottle for “Chain Gang.” It’s about having the nerve to sing “Matillda”—and the skill to sing it well—while rattling maracas and dancing around a plastic palm decked with bunches of fake bananas and strings of banana lights. More than anything, it’s about a kaleidoscopic three-minute homage to the Ed Sullivan Show—complete with drag flamenco, a “Lady of Spain”-playing accordionista, and stupid (stuffed) animal tricks—that is a total howl.

The cast members (Robert Hall Jr., Doug Sanford, Troy R. Miller, and Tom Manger) throw themselves into all this business with an astonishing geeky enthusiasm. Playing guys who met as members of the high-school audio-visual club (or, as one cracks, the “projector sector”), they’re either the four most convincing actors or the four most naturally awkward performers in the metro area. Manger’s bespectacled Smudge and Miller’s nosebleed-prone Jinx, especially, are paragons of endearing neurosis. The real miracle, though, is that they do all this without sacrificing the music, turning in polished performances of standards and obscurities alike.

Patricia D. Rohrer’s able work on the piano would have been better served by a more stately instrument than the Marquee’s humble upright, which doesn’t have a particularly resonant tone. And though the Plaids are quite able to keep the beat sans accompaniment, the evening couldn’t possibly work without Jack Coulter’s smooth, rock-solid bass.

One caveat: The Marquee, which inexplicably isn’t serving dinner these days, is charging $25 bucks a head for a 90-minute show. (At the Shakespeare Theatre, you could get four hours of Henry VI for that rate—until last weekend, that is.) Add in the Omni Shoreham’s $14 parking gouge, and you’ve got a pricey evening for two. Despite its innocent charms, Forever Plaid may not be worth the freight.CP