We’re seeing the “world premiere” of this film tonight

Gavin Poolman remembers using the film cans containing the only existing work prints of “Festival Express” for hockey goals. His parents were divorced, and his father, who was the original producer of the film, moved often. Young Poolman never could understand why his father insisted on lugging around this stupid collection of heavy film canisters. At one point, he dragged the cans out of the garage and stacked them in the street to serve as goalposts.

“Festival Express,” which will have its world premiere tonight at the UA Galaxy (followed by a party at the Great American Music Hall), is rock’s great lost concert film. The movie, which opens its theatrical run July 23 at the Bridge, features a cast of 135 drunken and deranged rock musicians — including Janis Joplin, the Grateful Dead, the Band, Delaney & Bonnie, Buddy Guy, Sha Na Na and others — rolling across Canada on a train in 1970, partying nonstop in between mini-Woodstock performances at outposts along the way.