John Mayer's song for Jennifer Aniston (+video)

John Mayer's new song is said to be about his doomed relationship with Jennifer Aniston. Photo / Dean Purcell

John Mayer has written a song as a "farewell letter" to Jennifer Aniston.

The musician - whose relationship with the Friends actress ended in 2009 - allegedly wrote his single Shadow Days for the 43-year-old screen star.

Apparently the 34-year-old singer - who has also dated Jessica Simpson and Jennifer Love Hewitt in the past - wrote the song from his album Born and Raised to find closure on his romance with Aniston.

Lyrics in the tune include anecdotes of his time on the road following their high-profile split.

They read: "You find yourself alone ... I found myself in pieces/ On my hotel floor/Hard times help me see/I'm a good man with a good heart/Had a tough time, got a rough start/And I finally learned to let it go."

A source told Us Weekly: "Shadow Days is about Jen. It really took him a long time to get over her. He really loved her a lot."

They added: "He wrote the song as a farewell letter knowing [Aniston] would hear it. Ultimately he's done a lot of self-reflection though and it he realises they weren't right for each other."

The on-off duo got together in April 2008 and finally called it quits late in 2009.

Jennifer has been with her actor boyfriend Justin Theroux for over a year now.

The source added: "[John and Jen] weren't right for each other, but he is really a good guy.

"He's looking for a nice, non-famous girl he can relate to ... He loved [Jen and Jessica] both but it really affected him emotionally and it wasn't worth it."

Watch the video for Shadow Days:

- Bang! Showbiz