Sir Paul McCartney turned down the chance to buy the publishing rights to Bob Dylan's songs because he didn't want the folk superstar calling him up to complain when he sold them.

McCartney, whose own Beatles tunes are the property of Michael Jackson, spent years investing in other people's songs when he first turned his attention to publishing.

He bought up Buddy Holly's back catalogue and a handful of his favourite standards, but he turned his back on the opportunity to make a fortune with Bob Dylan's hits.

He explains, "We considered it, but it seemed like too much responsibility. I didn't want him ringing me up at three in the morning, going, 'Why have you screwed up my songs?'"