Believe it or not, I was working the overnight shift in a small market prog rock underground radio station and those groups you mentioned, the deep tracks at least, were the ones played. Along with Hawkwind, Tangerine Dream, Strawbs, Nektar and others. I would mix in a more familiar song by very very early Styx or Bloodrock and it made for a wild night of music. It was completely free form, not corporate, We DJs chose the music , free from the Program Director's stares. He was in on it too. The local concerts featured some great great bands that never made it big, but drove the scene during that time period. Bands like Stone Ground Kelly, World Column, Syrup, Train City. What a tremendous time in music and the whole social scene that was. The Beatles were in their twilight, Viet nam was on the minds of every 18 year male, and "Dark Side of the Moon" was on its way.