Morton Subotnick, Touch (Columbia 1969)
Morton Subotnick is best known for Silver Apples of the Moon, which used the same type of early synthesizer (the Buchla Electronic Music System). Touch was recorded in Quad (!), although of course I ripped it in stereo ... this is only a small part of the album-length piece, but the section about two minutes into this clip makes my eyes start to bug and sparks shoot out of my ears. Lots of his recordings are available on CD or LP through his website, inclding several with two albums on one disc.
Morton Subotnick - "Touch (excerpt)"