Jazz originated in the late 19th and early 20th centuries within the African American communities of New Orleans, United States, as a unique fusion of African and European music traditions, including ragtime, blues, and brass band music. This new style was characterized by its improvisational nature, which set it apart from other forms of music at the time. Over the years, jazz has evolved through various styles and sub-genres, thanks to the innovative contributions of numerous musicians.

The evolution of jazz styles includes early jazz, which laid the groundwork for the genre with its polyphonic improvisation. The swing era of the 1930s and 1940s brought large orchestras and dance bands to the forefront, popularizing swing music. Bebop, which emerged in the 1940s, introduced complex harmonies and rapid tempos, challenging both musicians and listeners. Gypsy jazz, popularized by Django Reinhardt, is known for its passion and rhythmic drive. Hard bop combined elements of bebop with rhythm and blues, emerging in the 1950s. Cool jazz offered a more relaxed approach, gaining popularity in the late 1940s and early 1950s. Modal jazz, which emphasized chord patterns over traditional chord progressions, became prominent with albums like Miles Davis' "Kind of Blue". Latin jazz fused jazz with Latin American rhythms, becoming popular in the 1940s and 1950s. Free jazz, characterized by a lack of regular meter and chord changes, emerged in the 1960s. Fusion jazz combined jazz with rock and funk elements, becoming popular in the late 1960s and 1970s. Contemporary jazz continues to evolve, incorporating more contemporary music elements.

Jazz has had a significant cultural impact, spreading globally and influencing countless genres while fostering new waves of expression. Its roots can be traced back to a combination of African rhythms, European harmonies, and the blues, creating a rich tapestry of sound emblematic of America's diverse cultural heritage. Jazz has not only influenced other genres but has also embraced and integrated rhythmic patterns and musical forms from different cultures, especially Afro-Cuban music. It has been instrumental in bringing together various musical traditions and fostering unity through the power of music. The retention of African rhythmic structures within jazz has enabled it to resonate deeply with audiences, preserving its roots while evolving.

Key figures in jazz include Louis Armstrong, known for his inventive cornet and trumpet playing and for popularizing scat singing; Duke Ellington, a composer and bandleader who contributed significantly to the development and dissemination of early jazz; Billie Holiday, a vocalist who played a significant role in jazz's early development and international popularity; Miles Davis, a trumpeter and composer known for his leadership in several major jazz styles; and John Coltrane, a saxophonist and composer who was a highly influential figure in the history of jazz.

Jazz continues to be a dynamic force in modern music, with recent trends such as acid jazz and innovative fusion with electronic music underlining the genre's enduring ability to reinvent itself. The genre's rich history and its cultural significance are well-documented, making it an important part of music history and a vibrant element of contemporary music scenes worldwide.