The first three of these recordings are from Madison Square Garden
( Roberta Flac, Sha Na Na, Stevie Wonder also played)
These recordings were made as part of the 'one-on-one' benefit for the retarded.
I was at this concert, John Lennon played with Elephants Memory Band,
it was perhaps the loudest concert i ever attended.

The fourth recording, is a rather unusual version of Imagine, because
John plays acoustic guitar, rather than the usual keyboards.