A nocturne (from the French for "nocturnal") is usually a musical composition that is inspired by, or evocative of, the night. Historically, Nocturne is a very old term applied to night Offices and, since the Middle Ages, to divisions in the canonical hour of Matins.

The name nocturne was first applied to pieces in the eighteenth century, when it indicated an ensemble piece in several movements, normally played for an evening party and then laid aside. Sometimes it carried the Italian equivalent, notturno, such as Wolfgang Amadeus Mozart's quadraphonic Notturno in D, K.286, written for four lightly echoing separated ensembles of paired horns with strings, and his Serenata Notturna, K. 239. At this time, the piece was not necessarily evocative of the night, but might merely be intended for performance at night, much like a serenade.

In its more familiar form as a single-movement character piece usually written for solo piano, the nocturne was cultivated primarily in the nineteenth century. The first nocturnes to be written under the specific title were by the Irish composer John Field, generally viewed as the father of the Romantic nocturne that characteristically features a cantabile melody over an arpeggiated, even guitar-like accompaniment. However, the most famous exponent of the form was Frédéric Chopin, who wrote 21 of them. One of the most famous pieces of nineteenth-century salon music was the "Fifth Nocturne" of Ignace Leybach, who is now otherwise forgotten. Later composers to write nocturnes for the piano include Gabriel Fauré, Alexander Scriabin and Erik Satie (1919), as well as Peter Sculthorpe. In the movement entitled 'The Night's Music' ('Musiques nocturnes' in French) of Out of Doors for solo piano (1926), Bartók imitated the sounds of nature . It contains quiet, eerie, blurred cluster-chords and imitations of the twittering of birds and croaking of nocturnal creatures, with lonely melodies in contrasting sections.

Other examples of nocturnes include the one for orchestra from Felix Mendelssohn's incidental music for A Midsummer Night's Dream (1848), the set of three for orchestra and female choir by Claude Debussy (who also wrote one for solo piano) and the first movement of the Violin Concerto No. 1 (1948) by Dmitri Shostakovich. French composer Erik Satie composed a series of five small nocturnes. These were however, far different from those of Frédéric Chopin and John Field.

The first movement of Ludwig van Beethoven's Moonlight Sonata has also been considered a nocturne (certainly, Ludwig Rellstab, who gave the piece its nickname, thought it evocative of the night), although Beethoven did not describe it as one.

Nocturnes are generally thought of as being tranquil, often expressive and lyrical, and sometimes rather gloomy, but in practice pieces with the name nocturne have conveyed a variety of moods: the second of Debussy's orchestral Nocturnes, "Fêtes", for example, is very lively.

The word was later used by James McNeill Whistler in the title of a number of his paintings, consistent with his theory that fine art should essentially be concerned with the beautiful arrangement of colors in harmony. Debussy's nocturnes were inspired by Whistler's paintings . Several other artists followed suit.

"Ye Qu" ( ) is a song by Taiwanese artist Jay Chou, the first song of the album November's Chopin. The idea of this song comes from the Polish musician, Chopin. This song describes a sad love story involving a deceased lover. The song infuses rap and R&B to create a unique sound. It combines the classic song of Chopin's nocturnes and the beat of Jay Chou style with a lot of classic piano sounds.

"Nocturne" was the winning song in the Eurovision Song Contest 1995, performed in Norwegian by Secret Garden representing Norway.

The song is unusual for its relative absence of lyrics - with only 25 words being sung in the original Norwegian version and much of the rest of the song being given over to a violin intermezzo performed by guest Irish musician Fionnuala Sherry. While no other victorious song has featured so few words, Finland would go on to place 15th in the 1998 Contest with "Aava", which contains only six words repeated throughout the song. The victory also represented the second for composer Rolf Løvland, who had previously written "La det swinge". Additionally, it represented the first time in four years that Ireland had not won the Contest, thus bringing to an end the only hat-trick of victories in Eurovision history. Ireland would go on to win the next Contest, achieving the feat of four victories in five years. Both lyrically and musically, the song owes a debt to the New Age genre. Vocalist Gunnhild Tvinnereim sings that night and day are complementary to each other, and that their progress is natural.

As Norway had previously won the Contest in 1985 with "La det swinge", the second victory allowed the tongue-in-cheek tradition to emerge that Norway could only win in years ending with a 5, a joke referred to by the members of Bobbysocks at the Congratulations special in late 2005, Norway having entered "In My Dreams" that year and not achieved victory.

The song was performed fifth on the night (following Bosnia and Herzegovina's Davor Popović with "Dvadeset prvi vijek" and preceding Russia's Philip Kirkorov with "Kolibelnaya Dlya Vulkana"). At the close of voting, it had received 148 points, placing 1st in a field of 23.

Unusually, "Nocturne" was not released as a single in Norway itself. The first release of the song as a single would come in a comedic cover version by country-inspired band Dusty Cowshit.

The song was succeeded as winner in 1996 by Eimear Quinn representing Ireland with "The Voice". It was succeeded as Norwegian representative at the 1996 Contest by Elisabeth Andreassen with "I Evighet".