(French: “Nocturnal”), in music, a composition inspired by, or evocative of, the night, and cultivated in the 19th century primarily as a character piece for piano. The form originated with the Irish composer John Field (Field, John), who published the first set of nocturnes in 1814, and reached its zenith in the 19 examples of Frédéric Chopin. In Germany the nocturne, or Nachtstück, attracted composers from Robert Schumann to Paul Hindemith (Suite for Piano, 1922). At the turn of the century Claude Debussy (Debussy, Claude) most successfully transferred the genre to the orchestra with his three brilliant pieces so entitled. Later in the 20th century Béla Bartók (Bartók, Béla) developed a very personal night-music style of distinctly macabre quality, for example, in Out of Doors (fourth movement) and in the Fourth String Quartet (third movement).

The late 18th-century Italian notturno, a collection of lightweight pieces for chamber ensemble, bore little relation to the lyrical 19th-century nocturne. Like the serenades and cassations of Haydn and Mozart, however, it was intended, at least originally, for nocturnal, usually outdoor, performance.