For nearly the first half of the twentieth century, from about 1915 to 1955, jazz was the dominant form of popular dance music in the United States. Dance music and dance bands existed before jazz and, after the rise of jazz, there were still many dance bands that did not play jazz or used jazz elements only sparingly. And although for a certain period of its existence, jazz was dance music, jazz musicians were probably not attracted to this style of music primarily for this reason. From its earliest days, jazz seemed to have been music that, in part, musicians played for themselves, as a way to free themselves from the rigidity of standard dance or marching bands or other forms of commercial or popular music, which they found repetitive and unchallenging to play. Jazz originated early in the century with small bands of five-to-seven players in a style that became known as New Orleans, named after the place where the music, in its first iteration, codified itself. That style is now called Dixieland. Jazz was propelled commercially mostly by 12-to-15 piece big bands, usually with both a male and female vocalist, in a style that became known as swing during the 1930s. Swing was built around highly rhythmic riffs with strong soloists providing “breaks” or moments of spirited improvisation against backdrops of arranged composition. Although jazz has made use of many musical structures including blues, tango, African and Indian music; its most basic form is the 32-bar format of the American pop song, many of which by such noted composers as Harold Arlen, Jerome Kern, the Gershwin Brothers, Rodgers and Hart, Vernon Duke, and others, constitute the foundational repertoire of jazz. Gershwin’s “The Man I Love” is a standard example of such a song with its A-A-B-A typology. This song and most of Gershwin’s most popular tunes are standard fare for jazz musicians even today.