"Festival Express" is a delirious piece of pop ephemera, a time capsule set on the cusp between the Summer of Love and the Day the Music Died. A quick, efficient and affectionate document of a five-day concert aboard a train in 1970, Bob Smeaton's film features some rare and lovely performances -- onstage and off -- by the Grateful Dead, the Band, the Flying Burrito Brothers, Buddy Guy and Janis Joplin, among others.

But more than just a musical tribute, "Festival Express" documents a cultural sea change, when the hippie movement went from being about peace and love to being about getting more sex, more drugs and more rock-and-roll -- preferably for free. As much as "Festival Express" pays loving homage to some of pop music's most influential artists, it shows how the selfishness and greed of the fans began to supplant the brief idealism of the era.

"Festival Express," the concert and the movie, were conceived by Canadian concert promoter Ken Walker, who wanted to create a Canadian Woodstock. But instead of having thousands of kids tramping to one location, Walker hit on the idea of putting the musicians on a train that would make stops throughout Canada -- in Toronto, Winnipeg, Manitoba and Calgary, specifically. Instead of Muhammad going to the mountain, he explains in one of several present-day interviews in the film, the mountain would come to Muhammad.

It was a lovely idea, especially for the musicians, whose instruments were stored in the bar car, an arrangement that "worked out perfectly," according to one participant, "because the rest of the train was a bar!" Very quickly, the musicians came to cherish the after-hours improvisations and parties on the train more than the concerts themselves. From the first performance in Toronto, the shows became battle zones for protesters who didn't want to pay; they ultimately succeeded in keeping even more fans away. It's a scene that played out in an eerily similar way that very same summer in England, at the embattled Isle of Wight festival captured so vividly in Murray Lerner's 1997 film "Message to Love."

Even as Walker lost his shirt and some of the best bands of the time played to half-empty stadiums, no one let the bad vibes get them down. Cutting between live performances of songs (left blessedly intact) and reminiscences by those lucky enough to have survived their own lives and times, Smeaton captures the generosity and musical goodwill that kept the train going, even when hostile fans, an equally unfriendly press and opportunistic politicians turned against the artists on board. (The footage that Smeaton has edited together was stashed in the Canadian National Archives until it was discovered 10 years ago; he's done an efficient, sensitive job of assembling it, even if he often leans too heavily on "Woodstock"-esque split screens.)

As the bands knew, and as "Festival Express" demonstrates, it was really about the music. Fans of rock arcana will no doubt cherish a rendition of "C.C. Rider" performed by Ian & Sylvia and their band Great Speckled Bird (let the music critics debate whether Sylvia Tyson's warble was equal to that particular task); the Dead, the Band and the Gram Parsons-less Burritos all deliver impeccable performances. But the movie belongs lock, stock and bell-bottoms to Joplin, whether she's tip-toeing through an impromptu jam with Bob Weir and pedal steel player Sneaky Pete Kleinow, or belting out electrifying renditions of "Cry Baby" and "Tell Mama." The latter is delivered in the singer's vintage style, with rambling, bawdy digressions and a feather boa in her hair (she's still the only woman, alive or dead, who could cop that look and get away with it).

At one point, the train runs out of booze and the crew stops to drop $800 at a Saskatchewan liquor store, even taking their last display bottle of Canadian Club. "Most of us were new to drinking," recalls Weir, explaining that until then he and his peers had mostly stuck to LSD and marijuana. "But it worked out just fine." Indeed, as the train heads to its final stop in Calgary, the musicians get more and more wasted, a bittersweet spectacle considering how Joplin would die just months later. Still, as Joplin herself gallantly proves when she presents Walker with a farewell gift at the last show, she and her contemporaries possessed an ineffable quality of grace that managed to transcend their grossest excesses. Even at their most dissolute, these young, vibrant artists at the heart of "Festival Express" had, of all things, class.

Festival Express (90 minutes, at Cinema Arts Fairfax, AFI Silver Theatre and Loews Cineplex Odeon Dupont Circle 5) is rated R for profanity.

The Grateful Dead, above, and Janis Joplin in scenes from "Festival Express," which pays loving homage to some of pop music's most influential artists as it documents a five-day concert aboard a Canadian train.