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.
Mozart: Serenade No. 10
for 12 Winds & Contrabass in B-flat major, K. 370a/361 ‘Gran Partita’