"Glee" creator Ryan Murphy was delighted to receive unsuspecting fan mail from none other than Beatles star Paul McCartney.

Speaking at the Television Critics Association's summer meeting Monday, "I received some fantastic mixtapes from Paul McCartney a couple of weeks ago. I thought I was being punked!"

He added "It came out of blue in a package, handwritten, and it had two CDs and it said, 'Hi Ryan, I hope you will consider some of these songs for Glee' ... I had heard that he is a fan of the show. I was gob-smacked ... so of course we are going to do something with him."

McCartney is among many celebrities who have developed an interest in the hit show. Murphy revealed that Susan Boyle is in talks regarding a special appearance in a Christmas episode.