The American musician known as the "King of Rock and Roll," who popularized a new genre of music in the 1950s, is Elvis Presley. His unique blending of musical styles, including blues, country, and rock, revolutionized the music industry. Presley’s charismatic performances and distinctive voice captivated audiences, leading to numerous hit songs and films. His cultural impact extended beyond music, influencing fashion and popular culture, and earning him a lasting legacy as an icon in entertainment history.