The Who are an English rock band formed in London in 1964. Their classic lineup (1964โ1978) consisted of lead vocalist Roger Daltrey, guitarist Pete Townshend, bassist John Entwistle and drummer Keith Moon. They are considered one of the most influential rock bands of the 20thย century. Their contributions to rock music include the development of the Marshall stack, large public address systems, the use of synthesizers, Entwistle's and Moon's influential playing styles, Townshend's feedback and power chord guitar technique, and the development of the rock opera. They are cited as an influence by many hard rock, punk, power pop and mod bands. The Who were inducted into the Rock and Roll Hall of Fame in 1990.