Johnny Depp helped Patti Smith record the title track of her new album, 'Banga', by recording her singing a capella.
The Hollywood star - who is also a guitarist - worked on the track after helping the singer record her initial vocal idea.
She explained to Spinner.com: ''It's all Johnny Depp. He's a friend of mine and I got the idea for the song in my head. I told Johnny, 'I don't wanna forget this.' So he recorded me singing a capella.
''Then Johnny said he would send it to me so I wouldn't forget.
''And when I got it, he'd put drums, guitars, everything on it! So the first minute of the song is all me and Johnny Depp.
''What we did in the recording studio was the band listened to Johnny's track and then came in on the chorus.''
Another track on the album pays tribute to Amy Winehouse - who died of accidental alcohol poisoning last year - but Patti said she was careful not to romanticise the singer's self destruction.
She added: ''A lot of people think that because I admire a lot of musicians or artists who did have a self-destructive bent that I romanticise self-destruction. Well, I don't at all.
''In Amy Winehouse's instance, I really admired her as a singer. That girl was amazing. She sang songs from my generation - R&B songs and jazz and doo-wop - with no sixth degree of separation. She really comprehended this music and delivered something extra.''