Those of us who live in site-built homes (to borrow the coinage of a Midwestern friend’s cleaning woman) may have wondered from time to time what goes down in the house-on-cement-blocks community. Like a battered bottle of Tide, the subject has popped to the scurfy forefront of the zeitgeist lately (one example: the MTV reality show “Trailer Fabulous”), but has been rolling into shore since the early 1980s, when the comedian Tim Kazurinsky, playing the Hindu sage Habinagudtym Vishnu Verhere on “Saturday Night Live,” revealed the question he would most like to ask the Almighty: “What does he have against trailer parks?” Thanks to a foulmouthed but big-hearted new comedy by Betsy Kelso, set in a trailer holding pen in Florida called Armadillo Acres, we now have an answer. And thanks to her cheeky script, an infectious score by David Nehls, and a richly talented cast, we leave the theater wanting to plead for mercy for the undeserving trailer sinners – every last marker-sniffin’, spraycan-huffin’, pole-dancin’, bathrobe wearin’, spouse-cheatin’ one of them.

“The Great American Trailer Park Musical” features some of the most roof-raising girl-group singing (and hair-raising perms) since the Pointer Sisters circa 1982, or the Andrews Sisters circa 1942. The show opens on a cozy neighborhood scene: Three trashily done-up women – call them a yahoo sisterhood – gather around folding chairs on a green plastic lawn, surrounded by trailers striped like ribbon candy, and testify to the realities of life in their ‘hood. The marvelous set by Derek McLane (“I Am My Own Wife”) brings the Technicolor paintbox of Munchkinland to the wrong side of the tracks, establishing a high-lacquer mood. And when the trailer trashette trio – Betty, Lin (short for Linoleum – she was born on a kitchen floor), and Pickles (Linda Hart, Marya Grandy, and Leslie Kritzer, respectively) – rhymingly, unprintably run through the sordid rap sheet of their love lives in song, it’s impossible not to laugh.

Even if you don’t have a husband named Earl on death row, it’s easy to relate to slightly clumsy jilted girl lyrics like “I won’t stand for cheatin’ / ‘specially with the girl next door / What does he take me for?” It’s the human tragedy, turned into musical sketch comedy – the trailer park meets “South Park.” Mr. Nehls’s workmanlike lyrics don’t matter much; his tunes – intentionally derivative of late-1970s and early-1980s rock and R&B, from Meatloaf to Aretha Franklin – have such good bones that any old flesh on them hangs just fine; and under all the blue eye shadow and pancake makeup, the natural look is hardly a goal. In any case, the brio of the singers masks any flaws.

As Betty, Ms. Hart plays the group’s ringleader. She displays winning I-maybe-50-but-damn-I’m-still-hot moxie, and has Tina Turner charisma with the voice to match. Ms. Grandy, playing Lin (the future widow of Earl), gets most of the filthiest lines and has a soaring, expansive sound that has long been heard about town in smaller venues. Ms. Kritzer, as Pickles, a trailer wife who suffers from hysterical pregnancies, has a terrific comic presence that recalls Didi Conn’s turn as Frenchy in “Grease” (the movie). The women blend together stirringly; but when Orfeh, as a stripper named Pippi, makes the scene, her voice sets her apart, with power and soul that punch straight through the sternum and shake you into feeling. Unlike shows such as last year’s appalling “Brooklyn: The Musical” – which attempted to hide its saccharine sterility and fatuous storyline under a profusion of belted R &B ballads – “Trailer Park” doesn’t live on its music alone. This white-trash dumpster sparkles with treasure.

The play’s central drama begins when the exotic dancer Pippi blows into Armadillo Acres, on the run from a moronic thug named Duke (Wayne Wilcox). While dancing at the Litter Box Show Palace, Pippi accidentally runs into Norbert Garstecki (Shuler Hensley, in John C. Reilly mode) the paunchy toll-collector husband of an agoraphobic neighbor named Jeannie; before long, Pippi and Norbert start running into one another on purpose. Like a Greek chorus, the trashette trio shade in the story’s moral repercussions, chiding in close harmony, “You shouldn’t-a-couldn’t-a / Wouldn’t-a-oughtn’t-a done it.” It is a great musical moment, and also a use ful citation, as it contains no words that need censoring.

Jeannie, heartbroken, kicks Norbert out of the trailer, rueing the years of TLC she lavished on him – “You think those jalapeno Pringles cover themselves in spray cheese?” she wails. Then she has a nightmare (enacted by the cast) in which her troubles are broadcast on daytime television in a show headlined: “Strippers on the Run Who Sleep With Married Men Who Live in the Same Trailer Park and the Agoraphobic, Troubled Trailer Housewives Who Love Them.” The brittle, gloating moderator (Ms. Hart) mists up: “Ladies and Gentlemen,” she says, “Real tears. Real … American … tears.” After the miraculous appearance of a baby named Elvis, the battered hearts get a chance to mend. Pippi and Jeannie take turns delivering the show’s best song,” Make Like a Nail (and Press On). Pippi (Orfeh) owns the song, but when Jeannie sings, “Even Oprah can’t make over / The mess I’ve become / It is up to me, there’s no time to be / Livin’ life deaf, blind, and dumb,” the music’s swelling swoops should win over every Destiny’s Child fan in the seats who ever thought she was a “Survivor,” too.

So it’s not “West Side Story.” If you read Us Weekly and let your channel rest on “Entertainment Tonight” from time to time, do you deserve better? Do you even want better? Sometimes, as bad as it gets is as good as it gets.

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