Paul McCartney's only son and John Lennon's younger son released their first-ever collaboration with each other on Friday, April 12 Sadie Bell was a digital news writer on the music team at PEOPLE.

Plus What They're All Up to Now James McCartney and Sean Ono Lennon Team Up to Release Single 'Primrose Hill' Sean Ono Lennon Has Oscars Crowd Wish Mom Yoko Ono 'Happy Mother's Day' in U.K. While ...