The Everly Brothers rock groups of the 1960s. The Beatles, The Beach Boys, and Simon & Garfunkel developed their early styles by performing Everly songs. The Bee Gees, The Hollies, The Marmalade, and other rock and roll groups that feature harmony singing were also influenced by the Everlys. The music of the Everly Brothers influenced the Beatles, who referred to themselves as "the English Everly Brothers" when Paul McCartney and John Lennon went hitchhiking south to win a talent competition. They based the vocal arrangement of "Please Please Me" on "Cathy's Clown." Keith Richards called Don Everly "one of the finest rhythm players."
The Everly Brothers first time Don Everly had ever publicly supported a political candidate. Don stated that after his brother Phil's death, he felt free to express his political views more openly, noting that they held opposing political views which made it impossible for them to ever lend any active support to political candidates. Don and Phil, both guitarists, used vocal harmony mostly based on diatonic thirds. On most recordings, Don sang the baritone part and Phil the tenor harmony. One notable exception is "Since You Broke My Heart" (1958). Although Don was mainly low, and Phil was mainly high, their voices overlap