Producer Glyn Johns has worked with just about every great band worth talking about over the course of his long career. Now, Johns is giving fans an inside look at his career with his new memoir Sound Man on November 13th. One excerpt in particular, which was released today by Rolling Stone, has us really wondering about what could have been, though.

In the excerpt, Johns talks about encountering Bob Dylan at an airport. Dylan complimented Johns on his work with The Beatles, and the two talked about what The Beatles and The Rolling Stones were doing at the time when Dylan came up with a bright idea: a collaborative album between himself, The Beatles, and The Rolling Stones.

That collaboration sounds mind-blowing to music fans, but it was unfortunately not meant to be. Johns went to both bands with the idea, and the response turned out to be mixed. “Keith and George thought it was fantastic,” Johns writes. “Ringo, Charlie and Bill were amicable to the idea as long as everyone else was interested. John didn’t say a flat no, but he wasn’t that interested. Paul and Mick said ‘Absolutely not.'”

Now, Johns admits that the idea may not have worked. “However,” he wrote, “I would have given anything to have given it a go.”