Paul McCartney dropped by Graceland when he was in Memphis for his Out There tour on Sunday, and the ex-Beatle left a special memento behind: a guitar pick that he placed on Elvis Presley's grave.

McCartney said, on his Twitter account, that he was "paying respects." The Associated Press added that it was "so Elvis can play in heaven." The lifelong Presley fan also posted two photos: one features McCartney in front of the grave with the pick; the other is from inside Graceland with one of the King's guitars.

McCartney has recorded a number of songs associated with Presley over the years, including 'I Got Stung' and 'Party' on the 1999 solo album 'Run Devil Run,' 'That's Alright, Mama' from the Beatles' 'Live at the BBC' compilation and 'It's Now or Never,' which can be found on 'The Last Temptation of Elvis: An All-Star Tribute.'

The Beatles and Presley first met on Aug. 27, 1965, when McCartney showed Presley a few bass licks. "That was the great thing for me, that he was into the bass," McCartney recalled in 'The Beatles Anthology.' "It was a great conversation piece for me. I could actually talk about the bass, and we sat around and just enjoyed ourselves. He was great -- talkative and friendly, and a little bit shy."

McCartney's appearance at FedExForum was his first show in Memphis in two decades.