Per Google AI: The first major rock triple LP set was the Woodstock: Music from the Original Soundtrack and More album, released in August 1970. George Harrison's solo album All Things Must Pass followed in November 1970 and is considered the first rock triple album of new studio material. 

Recorded in 1963.

Yes! 2112 tour! First triple album set? 

Lara Manzanares: Yo Soy Ti

I've watched this so many times. What a live performer! Doesn't even need the mic.   Also, lots of Stax singles and demos