Paul McCartney has revealed how a rainy day inspired him to write a song about wife Nancy Shevell.

The singer famously wrote a love letter to his American heiress wife on Valentine’s Day while on holiday in Morocco.

In upcoming television documentary Live Kisses the musician is seen singing the track, called My Valentine, recorded for his album Kisses On The Bottom.

The former Beatles star wrote the tune on a rainy day while on holiday in Morocco as the couple about their hotel to keep dry.

Paul McCartney revealed: “We were on holiday together, Nancy and I, and it was raining, it’s kind of led me towards a kind of minor-y type thing and the sentiment of you know, oh it’s raining.

“I wrote the song on Valentine’s Day in Morocco where we were on holiday and it had been raining, and I’d said <<oh pity about the rain>> and all of that, and she’d said to me <<it doesn’t matter, we’ll have a good time>> – and I really liked that because I know there’s nothing you can do about weather.

“So I was in the foyer of the hotel, knocking around on this old Joanna that the Irish pianist played in the evenings and because it was raining, because it was not sort of sunny and bright and everyone milling around, this minor-y melody came out and the words were pretty much what I was thinking really, they just spilled out.”

Paul McCartney has revealed how a rainy day inspired him to write a song about wife Nancy Shevell.

Live Kisses documents a February night in Los Angeles – the very same evening The Beatles made their debut television performance on The Ed Sullivan show 48 years prior – when Paul McCartney decided to bring the tunes on his album to life.

He performed the songs at the Capitol Studios earlier this year where much of the collection was created and he is seen singing his love letter to Nancy Shevell live.

The recording took place hours after the long awaited addition of Paul McCartney’s star to the Hollywood Walk of Fame drew a traffic-stopping throng to pack the stretch of Vine Street in front of the famed Capitol Records building in Los Angeles.

And to add to the feeling of anticipation, the music had not been performed by the band of musicians before and the show was broadcast online live for the world to see.

The reunited all-star entourage included Grammy-winning producer Tommy LiPuma, Al Schmitt in the control room, musical director Diana Krall at the piano, and Kisses… players John Clayton, Karriem Riggins, John Pizzarelli, Anthony Wilson, Mike Mainieri and conductor Alan Broadbent.

Exclusive interview segments of Paul McCartney with Kisses On The Bottom collaborators Eric Clapton, Stevie Wonder, Krall and LiPuma, among others can be seen in the show which will be broadcast on Saturday.

The show will be broadcast on ITV1 at 11p.m. on Saturday 24 November

[youtube FUH05iJ3-Uo]