Taken from the book, he made more stage appearances than one might realise................(YouTube links are the ones I have found)
December 18th 1968 John and Yoko appeared at the Albert Hall, writhing on stage in a large white bag.
March 7th 1969 John and Yoko gave a concert at Cambridge
September 13th 1969 JL and the Plastic Ono Band held a Rock and Roll Revival Concert in Varsity Stadium, Toronto https://www.youtube.com/watch?v=1dnMz1oTdds
June 6th 1971 Frank Zappa, John and Yoko played together on stage at the Fillmore East, New York City https://www.youtube.com/watch?v=FjCSZR4dM_c
December 11th 1971 John and Yoko performed at a benefit for John Sinclair in Ann Arbor, Michigan https://www.youtube.com/watch?v=SLf2h64sP94
February 21st to 25th 1972 John and Yoko co-hosted the Mike Douglas Show for a week, on New York TV. During that week they played a session with Chuck Berry https://www.youtube.com/watch?v=kpTpxbnBWYM
August 31st 1972 John and Yoko headlined on "One to One" benefit concert for mentally retarded children held at Madison Square Garden, New York https://www.youtube.com/watch?v=gV43e_LJ3I4
November 28th 1974 Elton John and John Lennon appeared together on the stage of Madison Square Garden and sang "Whatever Gets You Through the Night", "I Saw Her Standing There" and "Lucy in the Sky with Diamonds"
(Tribute):- https://www.youtube.com/watch?v=qS8owINySCY
June 13th 1975 John performed on the television show "Salute to Lew Grade" in the U.S.
I did record this last concert on tape at the time and later trans. to DVD, and thinking I may post it to You Tube, but someone has beaten me to it.
AND there is a conflict in the dates, so take yer pick!!
YouTube blurb:-
John Lennon did not make many stage appearances during his short solo career after departing The Beatles. However, Lennon's final performance before a live audience is largely forgotten today. Lennon appeared at the Waldorf Astoria Hotel on April 18, 1975, to perform on "A Salute to Sir Lew Grade",
https://www.youtube.com/watch?v=wT6tm5BSY1M
Gordon - check out DaveTheUseless avatar!