(Gibson) "Valiant Paul McCartney, I presume?" said John Lennon. "Sir Jasper Lennon, I presume," responded Paul McCartney.Such was the manner in which the two former Beatles greeted one another when McCartney showed up, unexpectedly, at a recording session Lennon was conducting on March 28, 1974. In the throes of his "Lost Weekend" period, Lennon was in a Los Angeles studio overseeing production of Harry Nilsson's Pussy Cats album. Present were a number of players – including Stevie Wonder, guitarist Jesse Ed Davis, saxophonist Bobby Keys and Nilsson himself. McCartney was accompanied by his wife, Linda. Lennon's then-girlfriend, May Pang, was there as well.
"We had no clue he was coming," said Pang, referring to McCartney's visit in Peter Ames Carlin's recent McCartney biography, McCartney: A Life. "All of a sudden we turned around, and Paul was there."
So began the only instance in which, post-Beatles, Lennon and McCartney ever joined forces in the studio. Remarkably, although Pang had made reference to the event previously, it wasn't until May 1992 that McCartney confirmed that the studio reunion had occurred. "It's very difficult to remember those days, because it was all a bit crazy and everyone was getting out of it," McCartney revealed. "But yes, John was doing some recordings in Los Angeles and I showed up." - more on this story