Sir Paul McCartney relied on his four-year-old daughter BEATRICE to get a reaction to songs for his 2007 album MEMORY ALMOST FULL.
The former Beatle was writing songs for the LP when he played the youngster - his only child with ex-wife Heather Mills - a preliminary version of the LP's first single Dance Tonight.
And the star was convinced the song would be a hit after the tot joined in and danced along to the tune.
He says, "At home, I started stomping around the kitchen, playing this little instrument (a mandolin), just enjoying myself. I sang, 'Everybody gonna dance tonight'
"And my little girl came running in and started dancing, so I fell in love with the song."