Traditionally, scholars of the blues classify the genre into three categories: country, city, and urban. Country blues, widely accepted as its original form, refers to a solo singer accompanied by guitar, usually associated with the Delta; city blues refers to the blues songs and sound made famous by legendary women artists of the 1920s and 1930s: Mamie Smith, Bessie Smith, Gertrude "Ma" Rainey, Sara Martins, Trixie Smith, Clara Smith, etc. Blues accompanied by electric guitars, basses, and drums in the mid-twentieth century is generally considered urban blues. Despite these almost rigid classifications, the blues was, regardless of category, profoundly influenced by spirituals. In turn, the blues would become the most important influence in the development of jazz, providing it with a stylistic and technical model. From the blues, Jazz incorporated call and response, improvisation, and the emphasis on vocal sound, which is replicated by jazz instrumentation. Ragtime's syncopation and piano style are also critical jazz elements, along with several aspects of brass-band and syncopated dance music. Thus jazz engendered a new genre, and an indelible sound. Jazz is generally classified by region: New Orleans, Chicago, Kansas City, and New York, although fixed categories of jazz musicianship have been discredited by many eminent critics.

Compositions by Count Basie, Perry Bradford, Shelton Brooks, Duke Ellington, Ella Fitzgerald, W.C. Handy, and Fred "Jelly Roll" Morton are featured in this section.