Singer/songwriter Paul Simon insists his partnership with Art Garfunkel was strained, because he wrote all the songs.
The Graceland star, 64, claims their success was largely down to his songwriting, and as a result the lack of balance led to tensions.
He says: "A lot of the stress came from the fact that we had an unequal creative partnership. I wrote the songs, and that exacerbated the problems you'd get with any duo.
"The difference is that it's just me harmonising with myself now.
"I could have used Artie's voice. But if I'd done that, every conversation I'm now having would be about the disagreements the two of us had in the past."