Sean Lennon, the son of the late John Lennon, is preparing to interview Paul McCartney and Elton John to celebrate his dad’s 80th birthday.  The special will air on BBC Radio 2 October 3rd and 4th at 9 p.m BST.  Lennon’s half-brother Julian will also sit down for a chat on the same special.  In a preview of the upcoming interview, Sean talks to Paul about everything from his first meeting his dad John to the recording sessions for “Let It Be.”  What’s your most memorable John Lennon song?