What ought to be the biggest celebration in Woodstock in 30 years--the arrival of those pillars of the American musical theater, Sam and Wendy Gayle Schaeffer (think Comden and Green, think Nichols and May) at Appletop, the estate they've just bought--is marred, as usual, by the lowlife Driver family. This time, the trouble is with Lucille Driver, brained with a weed-whacker as she's cutting the lawn in Appletop's orchard. But her death is only the curtain-raiser in an all-out assault on her marijuana-growing husband and lying, raping sons. Who on earth would want to kill an entire family? Senior State Police Investigator Tom Wilder, enticed from the closet by the Schaeffers' fetching manager, Buddy Keeper, can't take a step outside his bed (or roll over inside it) without hitting somebody who'd be happy to take on the job, from abused cleaning woman Mary Margaret Mudd to arson victims Marc and Tiffany Markowitz to rival brush-cutter Wally Ellsworth. Despite the high death toll and the epidemic hatred of the Drivers, though, the tone here is so consistently, rather desperately zany that you keep expecting the rest of the cast to join Sam and Wendy in the musical interludes that first-timer Froscher scatters around as generously as red herrings. One thing's for sure: Those maniacally upbeat showbiz types sure knew where they'd fit in with the natives. ""Gay"" only begins to describe a latter-day Woodstock as consistently fey as if the whole town were made out of gingerbread.