Whether it was the LSD, the awakening of a collective consciousness, or simply the right convergence of trends, the music of the psychedelic era really did expand the horizons of what could be accomplished in a recording studio. The seeds of prog and all sorts of ambitious rock were sowed here, in multi-part suites from David Bowie and The Soft Machine, moody contraptions like “Time Of The Season,” and the undisguised mania of Arthur Brown, starting with maybe the best first five seconds in rock history.