Jazz is a music genre that originated in the African-American communities of New Orleans, United States. It originated in the late 19th and early 20th centuries, and developed from roots in blues and ragtime. Jazz is seen by many as “America’s classical music”. Since the 1920s Jazz Age, jazz has become recognized as a major form of musical expression. It then emerged in the form of independent traditional and popular musical styles, all linked by the common bonds of African-American and European-American musical parentage with a performance orientation. Jazz is characterized by swing and blue notes, call and response vocals, polyrhythms and improvisation. Jazz has roots in West African cultural and musical expression, and in African-American music traditions including blues and ragtime, as well as European military band music. Intellectuals around the world have hailed jazz as “one of America’s original art forms”. As jazz spread around the world, it drew on national, regional, and local musical cultures, which gave rise to different styles. New Orleans jazz began in the early 1910s, combining earlier brass-band marches, French quadrilles, biguine, ragtime and blues with collective polyphonic improvisation. In the 1930s, heavily arranged dance-oriented swing big bands, Kansas City jazz, a hard-swinging, bluesy, improvisational style and Gypsy jazz (a style that emphasized musette waltzes) were the prominent styles. Bebop emerged in the 1940s, shifting jazz from danceable popular music toward a more challenging “musician’s music” which was played at faster tempos and used more chord-based improvisation. Cool jazz developed near the end of the 1940s, introducing calmer, smoother sounds and long, linear melodic lines.