Sir Paul McCartney tours selectively.

The 69-year-old ex-Beatles musician initially started touring less because of custody arrangements between him and ex-wife Heather Mills of their eight-year-old daughter, Beatrice, but says it's become a good thing, as it means he's always feeling fresh.

He told Rolling Stone magazine: "We don't do the big sloggo tour, we don't do the big U2-Stones go-out-forever thing, and get a bit fed up with it.

"What we do now is events and selective dates. Because of my custody situation, I can only do that. At first, we thought, 'Oh, God, is this going to be a problem?' and it's actually turned out to be some kind of a blessing."

Paul also admitted he was originally told to retire at 50, as his manger thought it "get embarrassing" for him to still be on stage, but he laughed off his advice, and has no plans to stop soon.

He added: "I can imagine [performing in my 80s]. As to whether my imagination will come true, I don't know. The last couple of years, I've gotten into guitar - so there're all sorts of little things that crop up that entice you forward.

"If you're enjoying it, why do something else? And what would you do? For the time being, the band's hot, I'm really enjoying myself, still singing like I sang, not experiencing, touch wood, any sort of problems to speak of. If it aint broke, don't fix it.