Buddy Holly was a big influence on the Beatles, too. In fact, I can hear some Holly in the Everly Brothers. And some Everly Brothers in Holly.
Phil and Buddy were best friends but Buddy’s death devastated Don even more to the point he couldn’t even go to the funeral and wouldn’t fly on planes for years after.
Right before his death, Buddy was writing a song for Don and Phil and Phil and Buddy sang backup (falsetto) on a record Buddy produced for Lou Gordiano.
Both the Everly’s and Holly were huge influences not just for the Beatles but many UK artists of the 1960’s.
I have a great picture of Buddy playing a lick on his guitar, Jerry Lee Lewis watching Buddy like he is trying to change it over to piano, and Don just standing there, mouth agape, in awe.