Sir Paul McCartney feared his new album would ruin his career. The Beatles legend has just completed work on 'Electric Arguments', an ambient record with his side project The Fireman, which he says was recorded from entirely improvised sessions.

He said: "I had to make a disclaimer to the engineers. I said this could be the most embarrassing moment of my life. It was thrilling, but it could have been a terrible mistake. I could ruin my whole career."

The 66-year-old musician also revealed his hatred of working alone. Paul - who composed most of the early Beatles hits with the late John Lennon - says it gets too lonely if you don't have other musicians to discuss ideas with.

He added: "I like having a collaborator. Otherwise I get the feeling of being an absentminded professor alone in his laboratory all day. "I did the first solo McCartney record all on my own. It seemed a bit lonely.

There's a track on there that's about 10 minutes long. Try playing maracas for 10 minutes in a row on your own. I was standing in the room thinking, 'That's it - I've really lost the plot.' "