Although John Lennon and Paul McCartney contributed their share of love songs, McCartney was the Beatle who wrote the most throughout their career.

Bruce Springsteen is performing his first-ever shows in the Beatles' birthplace of Liverpool this week, so naturally Paul McCartney joined him onstage.

Cultural treasures like to hang out together sometimes. Paul McCartney and Bruce Springsteen have shared stages a number of times over the years — in London, New York, New Jersey, Glastonbury. Last ...