Birdsongs of the Mesozoic was so damn progressive that they considered their genre to be "Rock in Opposition." If you don't know what that means, basically it's a genre that is considered more of a social movement than a musical style. Another progressive band, Henry Cow, spearheaded the movement as an answer to the mainstream music industry that would not give bands like them a shot. It's not inaccurate to think of it as the anti-music industry, to put it in simple terms. Regardless of the social motivations, the talent is absolutely there with Birdsongs of the Mesozoic, and you can hear it in their complex arrangements and virtuosic musicianship.
What are your favorite musical social movements?