The Byrds were an American rock band formed in Los Angeles, California, in 1964. The band underwent multiple lineup changes, with frontman Roger McGuinn as the sole consistent member. For a short time in the mid-1960s, the Byrds were among the most popular groups in the world, with critics considering them to be among the most influential rock acts of their era. The band's signature sound of "angelic harmonies" and McGuinn's jangly 12-string Rickenbacker guitar sound was "absorbed into the vocabulary of rock" and has continued to be influential.