The cast of Concert for Bangladesh Revisited with George Harrison and Friends - 2005 includes: Eric Clapton Bob Dylan George Harrison as himself Jim Keltner Billy Preston Leon Russell Ravi Shankar Ringo Starr Klaus Voormann
The cast of Eric Clapton and His Rolling Hotel - 1980 includes: Eric Clapton as himself George Harrison as himself Elton John as himself Muddy Waters as himself
As far as live performances, George Harrison appeared on an episode of The Dick Cavett Show in 1971, in a band called Wonder Wheel. The band performed "Two Faced Man" which was written by Gary Wright. Harrison appeared as a favor to Wright, who had played piano on Harrison's album, All Things Must Pass.Speaking of concerts, however, I think you may be referring to his benefit concert, The Concert For Banga Desh. George held the concert to raise money and awareness of the starving refugees in Bangla Desh, the home country of his close friend Ravi Shankar.
George Harrison of Beatles fame wrote My Sweet Lord. It was released in 1970 seven months after the band broke up. It was Harrison's first single as a solo artist and was the highest selling single in 1971.
After the hiatus of the break-up had died down, all the Beatles were one reasonably good terms and kept in contact with each other. Lennon recorded with Harrison and Starr and occasionally met up with Paul. Lennon never recorded with McCartney, but there does exist a bootleg recording of Lennon and McCartney playing together in 1974. It's purely of historic interest only. _____ Not actively, after his 1975 reconciliation with Yoko Ono, and the dissolution of the Beatles's business partnership. Paul McCartney went through a period of turning up at the Dakota unannounced; Lennon visited with him a time or two, but turned him away on a subsequent visit, telling him "The old days are over." (He wasn't rejecting McCartney; he simply preferred that he call before he came by.) Lennon was upset with Harrison for being conspicuously absent from Harrison's autobiography I Me Mine, and was in no hurry to speak to him after it was published. Ringo Starr nursed a drinking problem from the 1960s to the late 1980s, and Lennon didn't want to be drawn into that. (He had had enough, drinking with Starr and Harry Nilsson in Los Angeles a couple years earlier.) Go Solo.
The cast of Sound of Music - 1970 includes: Barry Crocker as himself
The cast of Revisited - 2005 includes: Turner Crumbley as Nathan Pittman
The cast of Revisited - 2012 includes: Trevor Glen Campbell as Daniel
The cast of Holocaust Revisited - 2012 includes: Lewis Greenberg as himself
The cast of Linfield Revisited - 1973 includes: Homer Groening as Narrator
The cast of The Revisited Journey - 2004 includes: Leck Chanthanakone Veune Chanthanakone
The cast of The Poorhouse Revisited - 2011 includes: Derbhle Crotty Birdy Sweeney as Gravedigger
The cast of Mark of the Devil Revisited - 2002 includes: Udo Kier as himself
The cast of The Unknown Revisited - 2008 includes: Bruce Dale as Rescuer Dave McRae as Dave
The cast of Blerta Revisited - 2001 includes: Bruno Lawrence as himself Ian Watkin as himself
The cast of Betjeman Revisited - 1995 includes: John Betjeman as himself Nigel Hawthorne as Himself - Narrator
The cast of Dotcommies Revisited - 2003 includes: John de Rosier Korey Houska Sam Landman
The cast of Lucy in London Revisited - 2011 includes: Steve Binder as himself Dan Wingate as himself