McCartney is said to have recorded bass parts for the as-yet unannounced project, which is reportedly produced by Andrew Watt
The talk show host recalled having to convince the Beatles legend to follow through with the segment after getting "cold feet"
"His songs were distinctive and different from many others in the '60s and '70s..."
“I’ve always felt that the 1970s were the great under-examined part of his story”
The track was recorded in 1994 and has an environmentalist slant
"He's number one"
It happened while filming new Abbey Road documentary ‘If These Walls Could Talk’
The exhibit will open on June 28
The project captures the "pandemonium" of Beatlemania, and includes unseen portraits of McCartney's former bandmates