The spirit of D. Boon looms as a benevolent presence over "We Jam Econo: The Story of the Minutemen," a sad-happy documentary about the San Pedro, Calif.-based trio that redefined American punk rock in the early 1980s.

It's sad because singer/guitarist Boon died in a van accident in 1985, just as the Minutemen (including bassist Mike Watt and drummer George Hurley) were at a peak, opening for R.E.M. and blazing trails with the brief, blistering songs that gave the band its name. It's happy, too, because the Minutemen were great, and director Tim Irwin and producer Keith Schieron pay tribute with a film that ensures the band's place in the punk hall of fame.

The title is Watt's creed for the band's no-frills music and lifestyle, and the film follows suit: It's a rough-edged tale of friendship, combining 20-year-old performance tapes (including a sublime acoustic set from public-access TV) with present-day reflections by Watt (still deeply affected by Boon's demise), Hurley and a host of punk luminaries including Henry Rollins (Black Flag), John Doe (X), Jello Biafra (Dead Kennedys), Thurston Moore (Sonic Youth) and many more.

Their abundant praise speaks for itself: The Minutemen were influential then and now, and "We Jam Econo" is a valentine to the band and D. Boon's memory. They're immortal now, and that's as it should be.