The revered producer has been forced to retire because he no longer has the finely tuned ear which made him famous - and McCartney fears Abbey Road recording sessions with the Fab Four could be partly to blame.

He says, "We did listen to it too loud. He just got to the stage where he thinks, very nobly, that he shouldn't produce... I think it's very cool of him to know when not to do it."

McCartney wanted Martin to produce his new album CHAOS AND CREATION IN THE BACKYARD and when he couldn't persuade his old friend to return to the studio, he asked the producer to offer him an alternative.

He adds, "I just rang him up and said, 'If I can't have you, who's the man?' He chatted it around, thought about it, talked to his son, and a couple of days later he came back and said Nigel (Beck and Radiohead producer Nigel Godrich)."