Dir. Christopher Guest

Now playing at various theaters.

"Great! Can I have a fat ass?"

This, Christopher Guest tells me, was the immediate response of actress Jennifer Coolidge upon being invited to participate in Guest's new movie, A Mighty Wind. Best known for her roles in the Legally Blonde and American Pie flicks--as Reese Witherspoon's manicurist and Stifler's mom, respectively--Coolidge gamely signed on for her second Guest film, following her turn as a snow-pea-loving socialite with a "secret" Sapphic streak in 2000's Best in Show with A Mighty Wind's hilariously clueless, linguistically challenged PR maven, Amber Cole.

"Jennifer Coolidge wears bad clothes funnier than anybody since Imogene Coca," gushes castmate/longtime Guest crony Michael McKean in Wind's production notes. McKean's right, but what makes Coolidge's performance indelible is the crazy crap that comes out of her mouth.

"Amber's accent was based on a foreign exchange student I met in college," explains Coolidge, a veteran of the comedy troupes the Groundlings and Gotham City Improv, in Wind's notes. "Then [the accent] turned into something else; it sounds like a combination of Scandinavian, Czechoslovakian, and a deaf woman." It's also the funniest thing I've heard since Fabio got struck in the face by a goose.

As it turns out, Coolidge clocks only a couple minutes of screen time in Wind, which chronicles, in Christopher Guest's patented faux-documentary style, the planning and execution of a folk music concert, produced by the son of a newly late folk music mogul (played perfectly by Bob Balaban). The concert stars three of said mogul's most beloved acts: the troubadour trio the Folksmen (Guest, McKean, and fellow Spinal Tap-per Harry Shearer), long-estranged romantic duo Mitch & Mickey (SCTV legends Eugene Levy and Catherine O'Hara), and the explosively revamped New Main Street Singers, a screechingly upbeat folk "neuftet" featuring celebrated Guest veterans John Michael Higgins and Jane Lynch (in Best in Show, he was the kimono-clad Shih Tzu owner, she the sporting gal who suckled Jennifer Coolidge's snow peas).

Hovering at the fringes of A Mighty Wind's live-concert climax is Jennifer Coolidge's Amber Cole, kept company by the newest of the New Main Street Singers--Sissy Knox, played by Parker Posey, another Guest all-star sadly relegated to the sidelines in Wind.

But that's the way it goes in Christopher Guest projects, each of which--This Is Spinal Tap, Waiting for Guffman, Best in Show, and now A Mighty Wind--famously eschews pre-penned dialogue in favor of free-flowing improvisations from Guest's uniformly brilliant casts. Guided by outlines created by Guest and Eugene Levy, these improvisations typically fill upwards of 100 hours of film, which is then whittled down by Guest and an editor (Robert Leighton in the case of Wind) to form the 90-minute blasts of wit and humanity that have carved out a cinematic comedy niche all their own.

"You have to kill a lot of babies," Guest tells me, referring to the merciless procedure of turning 100 hours of film into a 90-minute feature. We're sitting in a suite at the Four Seasons, at a table filled out by Wind stars Harry Shearer, Fred Willard, and John Michael Higgins, who offer anecdotes of the film's docu-improv method, and provide impressive physical evidence that the funniest people in the world routinely line up to work with Christopher Guest.

Certainly one of the best things about A Mighty Wind is its music, all of which was written and performed by the cast, along with McKean's wife, Annette O'Toole, and composer C. J. Vanston--from the Folksmen's calamity epic "Blood on the Coal" (about a train wreck in a coal mine) to Catherine O'Hara's closing ditty about catheters, performed on an autoharp. In a rich twist, the film's soundtrack was produced by T-Bone Burnett, America's foremost "new folk" producer, most recently feted for assembling the gazillion-selling album (and subsequent tours) for O Brother, Where Art Thou? And just like Spinal Tap, there's a fair chance at least one of Mighty Wind's folk bands will have a life beyond the film.

"Last year, the Folksmen played a major folk extravaganza in honor of Harry Smith," Guest tells me. "After the show, one of the McGarrigle sisters told me that the folk scene is so much rougher than the rock scene. And she's right." Guest couldn't have asked for a better advance blessing for his film.

But back to Jennifer Coolidge: Could it be that she's the funniest woman in the world?

"Oh, yeah," Guest says. "She's hilarious."