Sir Paul McCartney used the songs on his latest album, 'New', to impress Nancy Shevell.
The legendary Beatles musician wrote the tracks for his current record when he first started dating the US businesswoman in 2007, and used to play her his compositions down the phone.
Speaking on UK TV show 'Lorraine', he said: "I started writing these new ones a couple of years ago when I was first going out with Nancy and I used to ring her up each morning, and I knew - because she was in New York and because of the time difference - I had a few hours to write something, so then I'd ring her up and say, 'Do you want to listen to a song?' It was a good motivation for me, it was like, 'Come on, get those done.' "
Paul, 71, added Nancy - who he married in 2011 - seemed impressed and didn't criticize any of his work.
He also addressed rumors he is planning to work with Radiohead singer Thom Yorke, saying the idea came from his fashion designer daughter, Stella.
He added: "Yeah, that's what Stella wants me to do. She's got great ideas, I can't always do them. A lot of them I do, because she's very much an ideas person.
"She wants me to do this, and she tries to put me with certain people she thinks I'd be good with."
'New' is released today (14.10.13).