TOM R writes:
Paul joined the other three ex-Beatles to work on Ringo’s song “I’m the Greatest”. He even suggested doing something more but John Lennon immediately balked and had no interest.
According to Lennon’s Playboy interview, in 1977–78, Paul used to show up at his Dakota apartment with his guitar and they’d hang out a bit. They even considered going to Saturday Night Live studios after Loren Michaels offered to pay $3,000 for the former Beatles to play one song but Lennon said when the time came, they were too tired to go. But at some point, Lennon said he told Paul to telephone before showing up because he was often busy taking care of Sean - and he thought Paul took it wrong.
After Lennon was killed, Paul provided backup vocals on George Harrison’s tribute to Lennon “All Those Years Ago”. Ringo played the drums though apparently not at the same time as Paul was in the studio.
In 1984, Paul released his studio album “Pipes for Peace”. On the song “So Bad”, Ringo played the drums.
In 1995, the three Beatles “reunited” to produce the mini-series “Beatles Anthology” and also recorded the songs “Free as a Bird” and “Real Love” that Lennon had written.
Jeff Lynne of ELO did the producing on Real Love and Free as a Bird.
When George was diagnosed with terminal cancer in 2001, Paul spent many days with George until he passed away.