This movie just opened in Boston. Here's a link to a review, and some excerpts:
The first Woodstock festival was endlessly documented, but the same can't be said for "Festival Express." Many music fans don't even know about it. The footage is only now surfacing of this extraordinary, five-day train ride and series of concerts across Canada that featured Janis Joplin, the Grateful Dead, Buddy Guy, the Band, Delaney & Bonnie, Ian & Sylvia, and the Flying Burrito Brothers.
It was 1970 -- a year after Woodstock -- when they all piled into a private train with a no-holds-barred attitude and engaged in boozy, all-night jam sessions that form the core of this startling film. Seeing Jerry Garcia break into a sudden gospel tune in the bar car, or tenderly kissing Joplin just months before she died, is the immediate stuff of legend.
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"You could drift from car to car and get involved in any number of jams, some of which did amount to some pretty heady stuff," says the Grateful Dead's Bob Weir, quoted in a latter-day, look-back interview in the film.
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it's the overnight jam sessions that steal the show. Surrounded by glassy-eyed musicians in the bar car, Garcia sings the gospel tune "Better Take Jesus's Hand" and blows everyone away. There's also a priceless, rather nongospel moment when the musicians run out of alcohol. Curiously, the train stops at some hideaway station that just happens to have a liquor store right next to the tracks. The musicians pool $800 to replenish their supply, and off they go.