In the early '70s, Kansas City was young, high and horny, and everyone went to the Ballroom

Mother Earth has left the building.

On a rainy night, the old hippies are being hustled out the door. It was supposed to be a reunion party for the radicals, scenesters and music freaks who, from 1971 to '74, frequented the rotting, rococo, hangarlike second floor of the El Torreon Building at 31st Street and Gillham, back when it was the all-rockin' Cowtown Ballroom.

A growing crowd of 100 or so people, mostly in their 60s, has come out for the second night of festivities surrounding the premiere of the locally produced documentary Cowtown Ballroom ... Sweet Jesus! Most of them haven't set foot in the place in more than 35 years.

The night before, at an advance screening at the Tivoli, many had watched themselves onscreen, talking about the years when rock superstars such as Alice Cooper, Van Morrison and Frank Zappa made the Ballroom the place to be for live music in Kansas City.

Tonight, the men who made the film invited them to return to their toking grounds. Joe Heyen and Anthony Ladesich spent the last two years interviewing hundreds of people and pulling together mountains of decades-old film reels, posters and photos to piece together their 85-minute love letter to the Kansas City of the early '70s.

But now, about an hour into the party, a representative from the Haddad Restaurant Group, which owns the building, arrives to shut it down. The cross-looking woman accuses Heyen of not having insurance or a permit or something. There's no liquor, so people have been milling around drinking soda while Chet Nichols strums his guitar, amplified by a small PA. Off in the corner, a flower child in a rain poncho twirls and pirouettes unselfconsciously through his entire low-key performance.

The party moves to the Tower Tavern, which in some ways is an improvement because there's a bar. Still, people are reeling a bit from having been kicked out of their old home away from home.

"There are a bunch of geriatric hippies celebrating something wonderful in their lives that happened in the '70s. That's threatening!" jokes Dan "Mort" Moriarty.

Moriarty was among the four founders of Good Karma Productions, which operated the Ballroom. "We wanted this San Francisco feel," Moriarty told me the night before. "What happened, in a totally miraculous way, was it had a Kansas City feel."

At the beginning of the film, between sound bites from Black Oak Arkansas singer Jim Dandy (who looks like he has lived about eight and a half of his rock lives and who says the Ballroom "was a social experiment in terror"), Michael Brewer of Brewer and Shipley says the biggest part of the '60s happened in the '70s.

That was certainly true of the Midwest. People of my generation won't recognize the Kansas City in the film.

For years, Volker Park (now known as Theis Park) was a mini-Woodstock every Sunday, entire hippie families filling the grounds from the Nelson-Atkins to Brush Creek for drug-addled, music-enhanced revelry. In Westport, head shops such as Tiny Tim's Magic Circus were everywhere.

Mary Ann Wynkoop, head of the American studies program at UMKC, gives the academic perspective on free love; singer-songwriter and '70s survivor Howard Iceberg sums up the layman's side: "It was a time when people enjoyed each other."

Why the fuck hadn't I heard of Fanny? The California four-piece (no pun intended) wasn't only the first all-female rock band signed to a major label but was also multicultural, with two members originally from the Philippines. Fanny played the Ballroom twice, in '73 and '74, and Cowtown features footage of the slender, longhaired "original godmothers of chick rock" living the teenage boy's rock-and-roll dream.

Handsome British bluesman Rory Gallagher guitar-gasmed for two and a half hours on 3/24/74, and Springfield's Ozark Mountain Daredevils, which got its start at the Ballroom, was the original Kings of Leon.

The film also touches on Kansas City's racial history, tracing the venue's origins as one of the nation's first integrated jazz clubs (est. 1927), through its two midcentury decades as a roller rink, to its zenith as the wild concert hall that hosted white bluegrassers the Nitty Gritty Dirt Band and black bluesmen B.B. King and Danny Cox.

And there was the war. In the film's most moving moment, local Vietnam vet Bill Beaumont talks about being under fire in the jungle. He reproduces, with eerie accuracy, the whistling sounds of mortar shells and describes the false autumn of falling leaves cut by bullets and shrapnel. After coming home, Beaumont threw himself into the Cowtown scene and designed posters for the venue.

Critics may say the film won't seem relevant outside Kansas City. But I think anyone interested in the history of rock and America in the '60s will find lots to love.

Certainly everyone in town should see it during its two-week run at the Tivoli starting May 22. More than anything, it shows — with humor, pride and vigor — a time more recent than the jazz era when KC was truly wild and cool.