Sir Paul McCartney has admitted that no artist he has ever worked has matched the songwriting standards of John Lennon.
McCartney, who has worked with the likes of Michael Jackson, Stevie Wonder and Elvis Costello, confessed that he has always thought twice before collaborating with other artists since The Beatles split.
"I'm a little bit wary of collaborating with other people because it doesn't happen as easily or as amazingly as it did with John," the BBC quoted him, as saying.
"It's a funny subject the collaboration thing because I collaborated with John and you're a little bit spoiled after that. That was one hell of a collaboration,” he added.
Sir Paul and Lennon met as teenagers in Liverpool, proceeding to form one of the most thriving and significant songwriting partnerships in musical history.
McCartney also added that he and Lennon “knew each other's minds”.
"I've done it quite a bit since and, I think - and I hate to say it - there's inevitably a sense of disappointment because it was just so cool for John and me to be working together, because we started so young and knew each other's ways and minds."