The story of the British rock scene from the early 1960s to the 1970s, well a kind of documentary. It is mostly a series of (mostly) great live performances - and some early music videos - interspersed with interviews.
If we are to be honest a lot of the interviews are not very illuminating (though Pete Townsend's anti-drug stance is interesting, as it comes alongside footage of Brian Jones' troubles). It doesn't really matter as the songs from the likes of the Rolling Stones, Cream, Crazy World of Arthur Brown, Joe Cocker and Jimi Hendrix (and many more) are incredible.
It is a bit of a hippy-fest, a film of it's time, but what a time.