Paul Simon was desperate to include Bob Dylan's "weathered" vocals on his latest album - and struggles to understand why his pleas for a collaboration went unanswered.
The singer was convinced the Blowin' in the Wind legend was a perfect match for the title track of So Beautiful or So What and begged Dylan to record a duet.
But Dylan, who toured with Simon in 1999, failed to get in touch.
Simon tells Britain's Uncut magazine, "I thought Bob could sing, put a nice voice on the verse from So Beautiful or So What that begins, 'Ain't it strange the way we're ignorant / How we seek out bad advice.'
"I thought it would be nice if he sang that, since his voice has become so weathered I thought he would sound like a sage. I sent it to him, but I didn't hear back. I don't know why."
But Simon took the snub in his stride, revealing he rarely gets into deep discussions about songwriting with his old pal.
He adds, "He's fun to be with (but) I never had a really serious discussion about songwriting with any of those guys I know. I've talked very little about songwriting with Paul MCCartney. I've never talked about it with Bob Dylan."