The trombone is the brass instrument that commonly uses a slide instead of valves and has a major role in jazz ensembles.
A telescoping slide changes the length of the instrument’s tubing, lowering or raising the fundamental pitch. Players also adjust their embouchure to reach different harmonic partials. This design permits smooth glissandos, one of the trombone’s most recognizable effects.
In jazz, trombones appear in small groups, big bands, and rhythm-and-blues ensembles. Their broad tone can support harmony, answer melodic lines, or provide powerful sectional riffs. The tenor trombone is the most common jazz model, while bass trombones supply a lower register.
Not every trombone lacks valves: some bass and specialty models include valve attachments. Nevertheless, the slide is the defining feature of the standard trombone and distinguishes it from trumpet and horn families, whose common orchestral models use valves.