Jazz is a genre of music that originated in the African American communities of New Orleans in the late 19th and early 20th centuries. It is characterized by its swing and blue notes, call and response vocals, polyrhythms, and improvisation. Influential musicians like Louis Armstrong and Duke Ellington helped popularize jazz, which has since evolved into various styles, including bebop and smooth jazz. Blues is a music genre that emerged from African American spirituals, work songs, and folk music in the Deep South around the same time. It often expresses themes of sorrow, love, and resilience, using a specific chord progression known as the 12-bar blues. Notable artists such as B.B. King and Muddy Waters have played significant roles in shaping the blues, which has influenced many other genres, including rock and roll and jazz.