The piece opens the opera's third act, set in Venice. It is sung by the characters Giulietta – the protagonist Hoffmann's love, a Venetian courtesan – and Nicklausse – Hoffmann's poetic muse, in disguise as his faithful male companion. In addition to the Venetian location it sets the seductive and sinister tone of the Venice act in general and of Giulietta's character specifically. The music reappears later in the act in a septet, "Hélas! Mon cœur s'égare encore," which was constructed by editors of the opera.
"Belle nuit" is in the 6/8 time signature characteristic of barcarolles, allegretto moderato. Approximately a minute of musical introduction occurs before the melody appears, although a flute accompaniment figure which suggests the melody, "suspend time" and creating anticipation for the melody before it begins, is played throughout the piece. Although it is sung by a juvenile male character, Nicklausse, in a "breeches role", and a female character, Giulietta, the fact of its being fundamentally a piece for two women's voices, intertwining in the same octave, means that in productions where Nicklausse has been played by a male baritone instead of a female mezzo-soprano, his part has been reassigned to a chorus soprano.
Carl Dahlhaus cites the piece as an example of the duplicity of musical banality: in the period of Wagner, when serious opera was marked by chromaticism, Offenbach used the Barcarolle's very consonance to give a sinister feel to the act throughout which it recurs. Dahlhaus attributes this effect to the contrast between the "physical" presence of the vocal line and the ethereal feel of the instrumental introduction, creating a "mirage." "Beneath the music we hear, there seems to be a second musical level descending into the abyss."
The Barcarolle does not originate in The Tales of Hoffmann; it was written in 1864 for Offenbach's Die Rheinnixen, where it is sung as "Komm' zu uns" by the chorus of elves in the third act. In Hoffmann, it appeared in the version of 1881; although the third act was cut at the premiere, the location of the second act (Antonia) was changed from Munich to Venice in order to retain the duet, which was sung by offstage chorus and soloists rather than characters.
The Barcarolle inspired the English composer Kaikhosru Shapurji Sorabji to write his Passeggiata veneziana sopra la Barcarola di Offenbach (1955–56). Moritz Moszkowski also wrote a virtuoso transcription of it for piano.