Us Weekly hears...that an A-list actor with a slew of swashbuckling flicks to his credit loves to jam with American Idol's Steven Tyler when he's not filming.

"He plays music and I call him [and say] 'I'm coming over, we're going to write a song together.' He's like 'yeah, come over…tell me if I'm playing "Seasons of Wither" right,'" Tyler says of his celeb BFF.

Do you know which star we're talking about? Leave your best guess in the comments section!