Almost all American composers of note belong to the 20th century, and include such names as Charles Ives, Aaron Copland, Samuel Barber, Roger Sessions and Virgil Thomson. Edgard Varese and John Cage have gained fame as experimental composers. It is through the development of popular music in the 20th century that the USA has dominated the western world. Jazz, a style of music created at the end of the 19th century by black Americans out of their gospel and blues songs, was being played all over the USA by both black and white musicians by the 1920s, and influenced the development of both dance music and popular songs in the 1930s and 1940s. After the Second World War jazz and popular music developed in separate directions. Black musicians created a more sophisticated style called bebop. The rhythm and blues music that derived from jazz, combined with aspects of country and western music, developed into rock-n-roll in the 1950s with the music of Bill Haley, Chuck Berry, Elvis Presley, Buddy Holly and others. In the 1960s some British groups, especially the Beatles and the Rolling Stones, became internationally famous and for a brief period popular music was dominated by developments in Britain. Since that time, rock has incorporated folk music, soul music has developed, and many social phenomena, such as drug culture, the civil rights movement and the peace movement, have found their expression in rock music. The musical has also made an important contribution to popular music. Developing from the British music hall and American vaudeville early in the 20th century, composers such as George Gershwin, Cole Porter, Rodgers and Hammerstein, Stephen Sondheim and Leonard Bernstein on Broadway, and Ivor Novello, Noel Coward and more recently Andrew Lloyd Webber in Britain, have made the musical into one of the most important forms of popular music.
