Jazz is a music genre that originated in the African American communities in New Orleans, Louisiana. Jazz developed its roots in ragtime and blues and was widely regarded as the pinnacle of African American music in the twentieth century, distinguished by the originality of its improvisation. The musical hallmarks or jazz are improvisation, syncopation, swing notes, and harmonic complexity. Jazz musicians improvise by using the existing chords in a song to produce short melodies to accompany the harmony. Swing is the rhythmic momentum that makes you want to dance. Most improvisation is impromptu musicians performing on the spot. Several genres contributed to the formation of jazz, including ragtime, blues, marches, African American religious music, European classical music, American popular music, and American musical theatre. There are many different types of jazz music. Swing music, Bebop, cool jazz, hard bop, model jazz, and free are sub-genres within jazz music. Although the historical narrative of New Orleans is the point of origin for jazz music, Chicago serves an important role in jazz music. New Orleans joined the trend across the south towards rigid Jim Crow Laws. Important jazz performers include Louis Armstrong, a famous trumpeter, and Duke Ellington. Overall, unlike other music genres, jazz has been one of the most influential.