As for other bands of the era that fit the progressive rock category, again, most of them have been mentioned. King Crimsons first two albums, "In the Court of the Crimson King" and "In the Wake of Poseidon" are simply brilliant, timeless classics, and two of the greatest rock albums ever made in the opinion of many, including myself. I saw them perform Court of the Crimson King" live when I was abut twelve and managed to sneak out for the concert with a friend and his older brother, an amazing experience.
Again, this band has always been composed of superb musicians, Rober Fripp wouldnt allow anything else, though I personally feel that the cast assembled for the first two was never equalled in song and overall album quality.
Ian Anderson, who I had the privelege to meet once, a long time ago, and Jethro Tull has a legacy of wonderful and completely original music, starting from Aqualung, Through Thick As A Brick, and onto Songs From the Wood, and especially, Heavy Horses, amongst the later efforts.
Emerson Lake and Palmer take a great deal of abuse for having been gulity of bombastic excess these days, and did, back then amongst critics. Mostly it was undeserved, and connected to their final albums which were a bit embarassing compared to the early ones. Still, Tarkus, Pictures At An Exhibition, and Works were albums that contained some great music performed by absolutely incredible musicians. I saw Works live one one of the few concerts where they had a full orchestra with them and it was an unforgettable experience, even all these years later. I have a large photo, from that concert, of Keith Emerson staring fixedly at his extremely customized and elaborate moog synthesizer on my wall to this day that I took in my brief existence as a rock photographer whilst in college.
