Sharin' and Karen

Considering the awfully tempting material Tom Ross and Morey Goldstein had to work with, their parody of the Carpenters could have been ruthless. They had a goofy drummer in an evening gown, after all; a brother-sister duo whose wholesome image and pretty tunes not only belied the tumultuous times, but their own experience, which famously concluded with Karen's syrup-of-ipecac-induced heart failure after a long bout with an eating disorder.

But A Karen Carpenter Christmas is an affectionate rather than mean-spirited musical spoof, maybe because Ross and Goldstein recognized that what they were working with was ultimately a pretty sad story. To their credit, though, it's still a warm and funny show: Karen has been offered the opportunity to star in her own Christmas special, but she has to come up with the concept, which will be hard since she's been trashed by Rolling Stone and subsequently lost her Christmas spirit. Luckily, a last-minute parade of friends and celebrity guests saves the day. Katie Guthorn's Karen bears a startling resemblance to the original, and a cast including Goldstein, composer J. Raoul Brody, and Ethel Merman Memorial Choir singer/co-founder Jo-Carol brings infectious comic zest to Carpenters songs, Broadway hits, and celebrity impersonations. The show, which returns for its fifth go-round by popular demand, opens at 8:30 p.m. Tuesday (and runs through Dec. 30) at the Marsh, 1062 Valencia (at 22nd Street), S.F. Admission is $15-17; call 826-5750.

-- Heather Wisner