United Kingdom, March 18 -- Natasha Bedingfield's 'Unwritten' was inspired by the Beatles.

The 42-year-old pop star enjoyed huge success with her 2004 single, and she's now revealed the inspirations behind her chart-topping track.

Natasha told the Guardian newspaper: "I was whisked off to Los Angeles to work with songwriting mentors, which upped my game but meant I missed my younger brother Joshua's 14th birthday. I hadn't had a moment to send him a gift, so I decided to write him a song. 'Unwritten' was written with a 14-year-old in mind.

"At that age, you're desperate to be taken seriously but at the same time everyone is asking what you're going to do. There's this huge pressure to map out your future.

"'Unwritten' started as a poe...