John Coltrane and Johnny Hartman

Cool jazz is a modern jazz style marked by relaxed tempos, lighter tone, and a focus on arrangement, counterpoint, and timbral clarity. It favors understatement over virtuoso display and uses dynamics, space, and balance to create an airy, "cool" ambience. Emerging in the late 1940s, the style drew on bebop’s harmonic sophistication while smoothing its angular edges, often incorporating classical techniques such as linear writing and orchestral color. Hallmarks include brushed drums, lyrical improvisation, careful voice-leading, and unusual instrumentation (for jazz) like French horn and tuba alongside trumpet, saxophones, trombone, piano, bass, and drums. Although associated with the U.S. West Coast in the 1950s, cool jazz originated in New York through sessions led by Miles Davis and arranged by Gil Evans and others. It went on to influence bossa nova, third stream, modal jazz, and later smooth jazz and lounge aesthetics.

Vocal jazz is a jazz tradition in which the human voice is treated as an instrument—matching the phrasing, articulation, and timbral nuance of horns or piano. Singers often improvise melodically and rhythmically, including using scat singing (nonsense syllables) to emulate instrumental solos. At the same time, many vocal‑jazz performances favor traditional, pop‑leaning song structures and clear lyric delivery, reducing the overall role of extended improvisation compared with small‑group instrumental jazz. Repertoires frequently draw from Tin Pan Alley and Broadway standards (the Great American Songbook), rendered with swing, ballad, or Latin feels.

Jazz is an improvisation-centered music tradition that emerged from African American communities in the early 20th century. It blends blues feeling, ragtime syncopation, European harmonic practice, and brass band instrumentation into a flexible, conversational art. Defining features include swing rhythm (a triplet-based pulse), call-and-response phrasing, blue notes, and extended harmonies built on 7ths, 9ths, 11ths, and 13ths. Jazz is as much a way of making music—spontaneous interaction, variation, and personal sound—as it is a set of forms and tunes. Across its history, jazz has continually hybridized, from New Orleans ensembles and big-band swing to bebop, cool and hard bop, modal and free jazz, fusion, and contemporary cross-genre experiments. Its influence permeates global popular and art music.