Dixieland all of the recorded repertoire of New Orleans musicians was from the period when the format was already evolving beyond the traditional New Orleans format. "Dixieland" may in that sense be regarded as denoting the jazz revival movement of the late 1930s to the 1950s as much as any particular subgenre of jazz. The essential elements that were accepted as within the style were the traditional front lines consisting of trumpets, trombones, and clarinets, and ensemble improvisation over a 2-beat rhythm. The Dixieland revival renewed the audience for musicians who had continued to play in traditional jazz styles and revived
Bop City War II. While modern jazz, whether in the form of swing or bebop, was popular on Los Angeles' Central Avenue, San Francisco was at the time a haven of traditional jazz (also known as Dixieland). In the 1940s and early 1950s, the Bay Area scene was dominated by Dixieland revival bands such as Lu Watters' Yerba Buena Jazz Band. In the late 1940s, however, new clubs emerged in the Tenderloin and North Beach districts, which changed the music scene in the city. Bop City emerged from the short-lived club Vout City, run by Slim Gaillard on the same premises. Gaillard