Duodecet

In music, a duodecet—sometimes duodectet, or duodecimette—is a composition which requires twelve musicians for a performance, or a musical group that consists of twelve people. In jazz, such a group of twelve players is sometimes called a "twelvetet". The corresponding German word is duodezett. The French equivalent form, douzetuor, is virtually unknown (in sharp contrast to "dixtuor", the French word for decet). Unlike some other musical ensembles such as the string quartet, there is no established or standard set of instruments in a duodecet.
History.
Of the ensemble types named according to the number of musicians in the group, the decet, undecet, duodecet, tredecet, etc., are names less common in music than smaller groupings (quartet, quintet, etc., up to nonet). In the eighteenth century, twelve-part ensembles were most often encountered in the genre of the wind serenade, divertimento, nocturne, or partita—for example, Josef Reicha's "Parthia ex D", for 2 flutes, 2 oboes, 2 clarinets, 3 horns, 2 bassoons, and double bass, and the partitas for the same instrumentation by Reicha's colleague Johann Georg Feldmayr. In fact, the titles "serenade" and "suite" continue through the 19th century to be the preferred term for ensembles of twelve or thirteen instruments, especially winds (e.g., Wilhelm Berger's Op. 102 for 12 winds, Felix Mendelssohn's Op. 24 for 11 or 12 winds, Max Reger's Serenade for 12 winds, or Richard Strauss's Opp. 4 and 7, for 13 winds). The word "duodecet" remains rare as a genre title in the 20th century (exceptions are found amongst the works of Polish composers Barbara Buczek and Bogusław Schaeffer), where works for twelve instruments or singers most often are given either a true title, or a genre title describing the form (e.g., "concertino", "suite", "variations"), often followed by a designator such as "for twelve instruments".
The three "twelve-part inventions", variations 3 (12 solo violins), 5 (10 violas and 2 double basses), and 11 (12 wind instruments), in Stravinsky's "" (1963–64) have been designated "duodecets" by his biographer Eric Walter White.)
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