When Sean Lennon joined Aerosmith Tuesday night at New York's Madison Square Garden to perform The Beatles' "Come Together," it was the second time this year they've worked with one of John Lennon's sons. His older son Julian, from his first marriage to Cynthia, sings on the song "LUV XXX" off of Music From Another Dimension. The album was produced by Jack Douglas who produced papa Lennon's last album, Double Fantasy, and was one of the last people to see him alive. Aerosmith performed "Come Together" in the critically panned movie Sgt. Pepper's Lonely Hearts Club Band.

Lennon also has a connection to opening act Cheap Trick -- the Tricksters, Rick Nielsen and former drummer Bun E. Carlos played on the Double Fantasy sessions, and Douglas produced three of their albums. 

On Thanksgiving 1974, John Lennon joined Elton John on stage at Madison Square Garden, which turned out to be his final performance. Backstage that night he reunited with his estranged wife, Yoko Ono, and the following January Sean was conceived.