Harlem rhythm, New Orleans brass quartets and Southern orchestras had been knocking on the doors of American popular music since its creation. By the 1900s, all three sounds combined in the heart of Tin Pan Alley and mainstream America.
Between 1900 and 1910, more than 1800 "rags" had been published, beginning with "Maple Leaf Rag" by Scott Joplin. Irving Berlin followed with "Alexander's Ragtime Band" in 1911. Ragtime is a strongly syncopated music in fast, even time--extremely rhythmic, and primarily centered around the piano. Ragtime led to the improvised breaks of jazz, spawned the Harlem stride piano music of the 20's and 30's and created the extended instrumentation utilized in symphonic jazz and "swing" music. It was a beat completely different than any that had existed before. It erased the 3/4 time of the Waltz and, using harmonically simple chords built on polka and march foundations, brought a new dance music with the straightforward down beats of 4/4 and 2/4 times.
Jazz-a combination of the Blues' 12-bar progression and Rags' emphasis on improvisation--adopted a slow, languishing rhythm that was fully recognized in popular music in 1917 with the recording of Louis Armstrong. The next decade was dedicated to the playing and recording of Jazz music. Bands and Vocalists of the 1920s--such as Paul Whiteman Band, Coon-Sanders Band, Guy Lombardo, Eddie Cantor, Sophie Tucker, Al Jolson and Rudy Vallee--saw the greatest outpouring of songs of any decade during Tin Pan Alley as popular music, and popular culture, embraced the new sound. It allowed for emotional passages by individual soloists or large brass ensembles with strings and drums. Jazz introduced a new harmonic vocabulary using dynamic rhythms and expressive vocals reminiscent of Southern plantation blues music.
In the mid 1920s, dances such as the Fox Trot, The Shimmy, The Black Bottom and The Varsity were sweeping America. One dance in particular epitomized America during this decade: The Charleston. James P. Johnson wrote "Charleston" in a stride style, which stresses a strong "swinging" bass while moving in a "stride fashion" with a single treble melody. Stride music, introduced in 1924 with "The Charleston", combined Ragtime syncopation and the smooth progression of jazz with livelier upbeat rhythms and a swinging bass that helped usher in the next decade's genre.
During the 1890s, John Phillip Sousa's Brass Band sound infiltrated American popular music, laying the groundwork for the orchestral and swing bands of the 1930s and 1940s. Benny Goodman, the "King of Swing," opened the door for hundreds of other bands and orchestras, such as Count Basie, Hal Kemp, Wayne King, Isham Jones, Art Kassel, Ted Fiorito, Ray Noble, Dorsey Brothers and Artie Shaw. Big band swing music used extended instrumentation with contrasting saxophones and brass elements, along with jazz-inspired improvisations. It was a new dance music, which reached its peak in the late 1930's, and featured new vocalists, such as Ella Fitzgerald and Billie Holiday.