I've been a progressive rock and metal fan for well over a decade now, and describing progressive rock to others has always been difficult. The recent Rush: Beyond The Lighted Stage documentary discusses one band's rise to stardom by pushing their musical talents and remaining true to their sound and principles. Yet BBC4's television program Prog Rock Britannia: An Observation in Three Movements discusses the rise of the progressive rock sub-genre by primarily examining the movements just prior to mainstream success in the mid-1970s.
Tracing the roots back to just after the psychedelia phase of rock n' roll, this documentary recounts the Canterbury scene in which free-Jazz and English-folk would form the foundations for the successful progressive rock bands. The Beatles' Sgt. Pepper's Lonely Heart Club Band and The Moody Blues' Days of Future Passed helped define the need for experimentation with music as well as how it was presented in the album cover. After Sgt. Pepper and Freak Out, the gate-fold cover became the essential way to distribute this new sub-genre of music (it also made for a great way to start to roll a joint, apparently).
As I mentioned in my