It's a mixed-up, mythical place where humans hang with Muppet-esque critters who wear their M (for Mature Audiences) rating like a flag. They sing! They dance! They fornicate!

The songs, by Robert Lopez and Jeff Marx, subscribe to easy, kid-friendly melodies that areusually dispensed on TV in children's programs, but their lyrics focus on the smarting concerns of adults (anyone, really, who has been smacked down a few times by Life). In the same relentlessly sunny way that life lessons are served to the small-screen small fry, these tunes address a new set of Three R's - Rent, Race, Raunch.

There are songs for interracial marriages, in this case Jewish-Japanese ("Everyone's a Little Bit Racist"), the English-challenged ("The More You Ruv Someone"), the closeted homosexual ("If You Were Gay"), the closeted exhibitionist ("I'm Not Wearing Underwear Today"), the amorously vocal ("You Can Be As Loud As the Hell You Want [When You're Makin' Love]"), the neighborhood perv who keeps to himself ("The Internet Is for Porn") and the agoraphobic among us ("There Is Life Outside Your Apartment"). In true TV-teaching tradition, some numbers come with visual aids — television monitors on opposite sides of the theatre that can finesse the word "purpose" into "propose" or spell out the word-of-the-day, "schadenfreude" (i.e., delight in the misfortune of other people).

All of the above are plopped down on a cartoony street in a still-affordable outer borough of NYC. Set designer Anna Louizos has devised a row of comfy/grubby tenement flats where puppets and live human beings can playfully interplay and coexist. One senses Mister Rogers lives just down the block.

"It all has that feeling of the safe space where you grow up," summarizes John Tartaglia, the youngest (25) of the four puppeteers in the cast, "kind of a wishful place. Anyone who moves to New York at a young age would want to live on Avenue Q. Neighbors talk to each other and get you out of your apartment and get on with life. That's what "Sesame Street" is. We all wish we could go to that special place where we all live in harmony." "We wanted it familiar so it's one less leap you have to make in your mind," seconds the second-youngest (31) puppeteer, Stephanie D'Abruzzo. "It's a New York from 20 years ago. Look at how these buildings are made — you don't see brownstones and walk-ups that look like this. It's more like the "Sesame Street" walkups of old — and even "Sesame Street" has gotten gentrified since then. This is more representative of your 1970's New York."

Tartaglia and D'Abruzzo have their hands full — literally — manipulating and vocalizing four major characters and the occasional bit part. The remainder of the puppet population is played by Rick Lyon, who designed the puppets, and Jennifer Barnhart. All hail from the House of [Jim] Henson and mesh with balletic grace.

"A lot of that has to do with the fact we've all worked with each other for a good long time — on "Sesame Street" and other Henson shows," notes D'Abruzzo, who just marked her first decade as a Henson puppeteer (Tartaglia hits his next year). "The New York puppeteer circle is pretty small — maybe 40 puppeteers who work in TV — and we wind up working on the same jobs, so we get to know each other and develop a certain rhythm."

All roads lead to "Sesame Street," but there's not an official intersection with Avenue Q. The rules of parody keep them separate, says D'Abruzzo. "If we were to skewer actual ‘Sesame Street’ characters — 'There's Big Bird, and he's doing crack' — it would be a different story. But these are original characters. They don't reflect on ‘Sesame Street.’"

Besides, adds Tartaglia, their Henson bosses are solidly on their side. "They understand we're actors away from ‘Sesame Street.’ They're all for us pursuing other projects."

There are three "live action" inhabitants of Avenue Q, two of whom marry during the course of the show — a hard-nosed Asian therapist named Christmas Eve (played by Ann Harada, like Margaret Cho in heat) and a hulking milquetoast (Jordan Gelber) who wants to be a comic but has trouble standing up to her.

The third human is the poster boy for schadenfreude, Gary Coleman, who here appears to have come out of his stardom nose dive — to become a building supervisor. And — talk about "Diff'rent Strokes"! — he is played by a woman (Natalie Venetia Belcon). "It was always a woman," admits Jeff Marx. "We didn't want to get a physical replica of him because that would be too weird. We thought if we went for the opposite it would be more fun, and the intention of it — the playfulness of it — would be clear. We picked Gary Coleman because of his attitude. He has been as high as one can be, and he has fallen pretty much as low as one can. He serves as an example of what we might become if we're not careful, of not feeling special because we're no longer a kid."

And what better way to break that startling news to you than in a Broadway puppet show?