Now this is high concept: In the summer of 1970, when rock-and-roll is peaking with raw energy and originality, a private train rolls westward across Canada carrying some of the greatest rock musicians of all time. Between scheduled concert stops, the passengers party day and night, boozing, debauching, getting wasted -- and making music they'd remember the rest of their lives.

That wild locomotive ride from Toronto to Calgary 34 years ago, called "the Festival Express," is one of rock history's overlooked footnotes, a musically momentous moment that passed like a train in the night.

Aboard were rock legends at the height of their careers: Janis Joplin, Jerry Garcia and the Grateful Dead, the Band, Traffic, Ten Years After, New Riders of the Purple Sage, Delaney & Bonnie & Friends, and the Flying Burrito Brothers, among others.

"Woodstock was fun but nothing like the Festival Express from a musician's standpoint," says Grateful Dead guitarist Bob Weir. "It seemed like a real fun thing to do and -- as I remember it -- it certainly was."

And like a Woodstock on wheels, the 2,200-mile concert tour was documented by a film crew, intended at the time to become another cinema verite movie. But financial problems, creative squabbles and lost canisters of film iced those plans for three decades.

Now the never-released footage has been rediscovered, and the rockumentary "Festival Express" opened yesterday in three theaters in the Washington area (Cinema Arts Fairfax, AFI Silver Theatre in Silver Spring and Loews Cineplex Odeon Dupont Circle 5 in the District). The film is a 90-minute flashback of a rare time and place when, for these musicians, it was all about the music.

"The whole concept was, let's put a couple of cases of tequila on the train and let the musicians have a good time," says the film's music mixer, Eddie Kramer.

"They didn't want to get off," says Kramer, the legendary technician who produced and engineered Traffic, Jimi Hendrix, the Rolling Stones and other rock hall of famers. "They were having too much fun."

From the film's opening, appropriately to the tune of the Grateful Dead's "Casey Jones," the ride looks more than fun. It was a runaway train driven by collective creativity. Grateful Dead drummer Mickey Hart, who last week ended a summer tour with Weir and other surviving members of the band, says the trip was a "sociological experiment."

Unhampered by managers, handlers, lawyers, agents, record execs, groupies and guards, the musicians discovered a meeting of the minds. "No one was playing their own tunes," Hart says. "Everybody was trying to make music -- communicating on a deep-soul level and using sound as the metaphor. Things that were done there have never been done since."

Different cars were equipped for different styles of music -- a blues car, a rock-and-roll car, a country car, an anything-goes car. But soon after the first "all aboard" was called, cross-style jamming began.

In one of several spontaneous gatherings, Garcia, the San Francisco psychedelic-rock guitar master, harmonizes on a soulful "Better Take Jesus' Hand" with Canadian country singer Sylvia Tyson of Ian & Sylvia. In another, rough-edged blues man Buddy Guy, who was at the beginning of his career, vocalizes on "Baby Here I Come" with Rick Danko of the Band.

"We were just drunk and loose and playing music constantly," recalls Hart. "We would just move from one car to the next and play, play, play until you dropped, then you got up and had a cup of coffee and went at it again."

At the concert stops, where audiences paid $16 a ticket to see a star-studded show, the bands played their own stuff, often with a little help from their friends. As Ian & Sylvia's band, Great Speckled Bird, is covering "C.C. Rider," Garcia laughs in admiration of guitarist Amos Garrett's licks. For Joplin's showstopper versions of "Cry Baby" and "Tell Mama," everyone stood back in awe.

"I'd seen Janis hundreds of times," says Hart. "I've seen her better, but I've never seen her better on film."

A memorable highlight on the film, sociologically if not musically, is a liquor-and-drug-soaked collaboration. An out-of-it Danko and a heavy-lidded Joplin slur out the old Huddie "Leadbelly" Ledbetter song "Ain't No More Cane on the Brazos," while Garcia, spaced-out and smiling, noodles the guitar, often off-chord. A soused John "Marmaduke" Dawson of the New Riders just grooves.

Unfortunately, what isn't in the film is what happened the next morning, says Buddy Cage, the steel guitar player for Ian & Sylvia who would join the New Riders soon after. "I'm sitting in the very same bar car and here they all come in. Garcia has his guitar and Rick Danko staggers in and Janis is there and Ian and Sylvia are there, and they start singing it again. That next day, the five-part harmony would've just blown your head off."

One oddity is that the train ride was so alcohol-influenced when many of these musicians ran back then on psychoactive drugs and weren't used to heavy drinking. But the promoters had warned the musicians against smuggling pot across the Canadian border. Hart remembers Joplin emptying a liquor store's shelves in Toronto to stock the train and the promoters making an unscheduled stop in Saskatoon to purchase more booze.

"We'd go out every once in a while between the cars and just throw up and then go back to playing," he says.

But one of the Grateful Dead's crew spiked a gigantic bottle of Canadian Club whiskey with hallucinogens, Hart says. "Everybody was in one state or another of an altered state."

Though this disoriented express was barreling through the era of free love, the film contains not even a glimpse of nudity and little suggestion the musicians were anything but abstinent (the film is rated R for language). But Hart expands the record: "Everybody was making love to everyone else," he says. "I slept across from Janis. . . . I can't speak for everybody, but I can speak for me and Janis. It was the love train, baby!"

Yet the "Ain't No More Cane" scene is a sobering reminder: Joplin, then the queen of the blues, would die of a drug overdose two months later at 27. Garcia died of drug-related heart complications in 1995 at 53. Hard-living Danko died of a stroke in 1999 at 56.

"It's a particular moment in time in the music world where we were almost at a crossroads and everything goes a little bit downhill after that," says Kramer.

As did the trip's finances, which were at rock bottom before the train left Toronto. Each concert stop, in Toronto, Winnipeg, Manitoba and Calgary, was disrupted by protesters demanding free music, which caused paying fans to stay home. The half-empty venues were financial disasters.

A lean and youthful Weir took umbrage in the film and he still does today: "It was absurd. What was it? A $16 ticket? They didn't take into consideration that it cost us plenty of money just to get there. If the whole show had gone smoothly, nobody was going to make a whole lot of money."

Says "Festival Express" producer Gavin Poolman, whose father was the original producer of the trip: "This train thing, this crazy idea that everybody had a fabulous time doing, wasn't the best business idea in the world -- but so what?"

In the context of the times, none of it was that crazy. Those days were dominated by civil unrest, an unpopular war in Vietnam, protests. It was 1970, the year the Chicago Seven got off on charges of conspiracy to incite riots at the 1968 Democratic National Convention. That spring, President Nixon's daughter Tricia invited Grace Slick of Jefferson Airplane to a party at the White House -- but when Slick showed up with Yippie Abbie Hoffman, one of the Chicago Seven, both were turned away. And U.S. forces crossed into Cambodia to hunt for Viet Cong bases in late April. Within a week, National Guardsmen had fatally shot four Kent State University students protesting the Cambodian invasion.

"The concerts were a bit of a mess, to be honest. . . . That's what was going on. The political context of the time was really quite significant," says Poolman.

The financial problems nearly snuffed the documentary. "By the time they got to Calgary, they didn't have any money and the cameraman was walking away with rolls and rolls of film, and it just lay there for years and years," says "Festival Express" director Bob Smeaton, who won Grammys for his documentary on Jimi Hendrix and his Band of Gypsies and "The Beatles Anthology" TV series.

A client of Poolman's father knew of the tapes and went on a search. Six years ago, he found negatives wasting away in the Canadian National Archives. Poolman had thirty-some hours of "work print" in canisters from his childhood, when he used them as street hockey goal markers. Eventually all but about 20 hours was recovered.

Poolman raised $3 million by showing investors a 15-minute teaser and the project was back on track. Smeaton tackled 60 hours of unedited onstage and on-the-train footage. "It was a treasure trove of fantastic footage," says Smeaton. "But it was like I'd been given a jigsaw puzzle without a lid on the box. Where do you start?"

Kramer, meanwhile, removed the crackles, snaps and pops of more than 80 hours of audio until "it sounded exactly how it sounded onstage -- only better," he says.

And it all had to be synced with the video. "Figuring out what performances went with what sound, that was the challenge," he says. "This movie could never have been made in '71 because the technology didn't exist to do it."

What was left on the cutting-room floor amazes Kramer. Traffic was recorded at the Toronto concert doing a version of "Feelin' Alright" that he says was the best he'd ever heard -- but there was no video.

And during the end credits, audiences will hear Joplin doing "Me and Bobby McGee" on the train. "It was the very first time she actually recorded the song," he says, but the video couldn't be recovered.

"It makes you think, huh?" says Poolman. "Bob Weir was 22. Jerry was 26. Janis was 27, Rick Danko was 23 or 24. We think of them as the legends of rock. But they were kids. Who do we have like that now of that age?"

Buddy Cage says the times are different now. At a special premiere of the film in Los Angeles, "two young people came up to me and the guy said, 'Look, was any of that scripted?'

"It stung me for a minute. I said, 'You poor [expletive], you weren't born then. What you got now is reality TV.' "

The train that carried a group of '70s musical stars on a five-day Canadian concert tour. The footage that was shot was lost for almost 30 years. Jerry Garcia of the Grateful Dead and Janis Joplin are two of the performers on the wild train ride that became a nonstop musical party between stops.