Sir Paul, Katy Perry trade songwriting tips

This CD cover image released by Hear Music shows "New," the latest release by Paul McCartney. (AP Photo/Hear Music)

LONDON (AP) — Even a star who has been performing for more than 50 years sometimes wants a do-over.

Sir Paul McCartney sang his new song "New" at a taping of "The Graham Norton Show" in London on Thursday — then decided he wanted a second take. The former Beatle's instincts were right on target: round two had much more verve.

McCartney and pop princess Katy Perry also gave a master class in songwriting at the taping. McCartney says he and late writing partner John Lennon expected to come away with a song every time they brainstormed. Perry, who says she's "an observer of life," carries around a recorder to stash away phrases that strike her fancy.

McCartney later treated the audience to a rousing song not on his new album: "Lady Madonna."