The Children In Need charity single, which was released on Monday, is competing for the Christmas number one spot.
"It's mental!" Jones told Digital Spy. "It didn't come about through me and it wasn't my idea!
"One of Terry Wogan’s people came up with the idea of people at Radio 2 recording an album for Children In Need.
"Then they asked me, 'Have you ever seen Bing Crosby and David Bowie's duet - what are you doing the week after next?' I said 'Why?' and they said, 'Because we've booked Abbey Road and we want you and Terry to record it'.
"Having picked myself up off the floor and dusted myself down, I said. 'What the hell, let's do it!'"
He continued: "So off we went to the studio, down the steps past all the Beatles history, with Terry complaining that his knees are hurting him. Then all of a sudden, I'm stood there singing and Terry Wogan's next to me going 'pah-pah-pah' - it was surreal."
When asked about his chances of beating the X Factor winner, Jones joked: "I don’t think we stand a chance in hell!"