Discipline by King Crimson
Honestly - you should really just go through their discography in full sometime.  There are a lot of great tracks off In Court of the Crimson King (I Talk to the Wind being a favourite of mine) along with Red (Starless being one I'd highlight).  It's a band that sort of faded into obscurity IMO - being muscled out by bigger names from that era like Yes, Genesis and Pink Floyd, all of which are definitely worth listening too, but King Crimson has got something special.