Sons of John Lennon, Paul McCartney, George Harrison and Ringo Starr are said to be planning to form a band.  The possibility that Sean Lennon, James McCartney, Dhani Harrison and Zak Starkey might do it went public in a recent interview McCartney's son did with the BBC.  James has appeared on albums his father and late mother, Linda, recorded and put out his own solo project in 2012. Sean, the son born to John Lennon and Yoko Ono and the younger half brother of Julian Lennon, has performed on albums done by his mother.  He was only 5 when his father was killed. Dhani Harrison helped complete Brainwashed, the album George Harrison was working on at the time of his death in 2001 and later formed his own group, thenew02.  Drummer Starkey has been the semi-official member of the Who in recent years and has also kept the beat for Oasis.  Even if the sum of their talent wildly exceeds each individual's, coming up with anything remotely close to as good as anything their fathers produced together would be remarkable and, fair or not, they certainly realize that's what it would be measured against by most people.