Jazz music is a unique form of musical expression, developed by African Americans and influenced by both European harmonic structure and African rhythms. It is a combination of ragtime, marches, blues, and other types of music, and it has evolved over time from being primarily for dancing to being appreciated as a form of art. Jazz has been the undisputed popular music of the United States since the Swing era of the 1930s and 1940s, and it has continued to evolve with innovations such as bebop in the 1940s and the cutting edge in the 1960s. The most likely explanation for how jazz music started is that some New Orleans musicians took the music they heard at home, in church, and in bars, combined it together, and created a new sound.
This new sound was characterized by syncopated rhythms, polyphonic ensembles, varying degrees of improvisation, deliberate deviations in tone, and the use of original timbres. It was a music that made people feel free and calm, and it made them want to get up and dance. The first jazz recordings were made in 1917 by The Original Dixieland Jazz Band, which helped bring the music to enthusiastic audiences across the country. New Orleans' musicians and musical styles continued to influence jazz nationwide as the music underwent a rapid series of stylistic changes.
In the 1970s, musicians such as Betty Carter and Art Blakey and the Jazz Messengers retained their conservative approaches to jazz in the midst of fusion and jazz-rock. They endeavored to find younger generations of staff to play authentic traditional styles such as hard bop and bebop. In Europe, creative jazz centers have been developed since the 1960s. Amsterdam's free jazz scene was documented by critic Kevin Whitehead in his book New Dutch Swing.
Pianist Brad Mehldau and The Bad Plus have explored contemporary rock music in the context of the traditional jazz acoustic piano trio, recording instrumental jazz versions of songs by rock musicians. Pianist Keith Jarrett established his so-called 'Standards Trio' in 1983, which has performed and recorded mainly jazz-standards. Jazz critic Joachim-Ernst Berendt argues that his terms of reference and definition should be broader, defining jazz as a form of artistic music that originated in the United States through the confrontation of blacks with European music. He argues that it differs from European music in that jazzy has a special relationship with time defined as 'swing'. A more precise term could be Afro-Latin jazz, since this subgenre usually employs rhythms that have a direct analogue in Africa or exhibit an African rhythmic influence beyond what is normally heard in other types of jazz.