It’s pretty much accepted now that Big Star are one of the most influential bands of the past 40 years, even though nobody bought their records when they came out in the ‘70s. Thanks to a steady stream of indie rockers who’ve declared their love for the power-pop group – starting with early-‘80s pioneers like the Replacements and stretching all the way to modern-day song architects like Wilco -- Big Star are one of history’s great lost bands.

They formed in Memphis in the early ‘70s after Alex Chilton’s first band, the Box Tops (who had a No. 1 hit with ‘The Letter’ in 1967, when Chilton was only 16), fizzled out. Along with singer-songwriter Chris Bell, Chilton wrote and sang songs that sounded little like the blue-eyed soul of his teens. Instead, Big Star’s music was jagged, melodic and made to be blasted out of car radios. But the band’s two albums – 1972’s ‘#1 Records’ and 1974’s ‘Radio City’ – flopped, and the group disbanded soon after the release of their second LP.

Bell died in 1978, the same year Big Star’s third album, ‘Third / Sister Lovers,’ was cobbled together from sessions Chilton recorded with the band’s drummer in 1974. It’s a dark, brooding masterpiece worlds away from the sunny guitar-pop of the other two albums. The group’s story is chronicled in the documentary ‘Big Star: Nothing Can Hurt Me,’ which charts the band’s rocky formation to its tragic end (Chilton, who enjoyed indie-hero status from the ‘80s until the end of his life, died in 2010).

The movie’s soundtrack includes 22 songs that span the band’s career. And it’s more than just a repackaging of tracks from the three LPs (2005’s reunion record with members of the Posies is rightfully ignored) -- the album features alternate takes, new mixes, demos and solo cuts by Chilton and Bell. All of them are previously unreleased. And all of the essentials are included: ‘In the Street,’ ‘The Ballad of El Goodo,’ ‘Thirteen’ and ‘September Gurls.’

Only the most compulsive fans will be able to spot the differences between the ‘#1 Record’ version of ‘When My Baby’s Beside Me’ and the alternate mix included here. So in that sense, ‘Big Star: Nothing Can Hurt Me’ is a respectable primer for the uninitiated and a fresh look at old classics for the completest. But you should really own the three original albums. The real history was made there.