In music, the duodecime (from Latin duodecimus : "the twelfth") is the twelfth level of a diatonic , heptatonic scale and the corresponding interval , which is made up of octaves and fifths and thus spans twelve levels, e.g. B. c-g ' . The (pure) duodecime comprises nineteen semitones. Musically it is like the fifth, i. H. treat as consonance .
The frequency ratio of a duodecime is 3: 1. It is therefore ideal as a scale frame for the Bohlen-Pierce scale .
Reed instruments with cylindrically drilled tubes (e.g. clarinet , crumhorn ) overblow for the first time in the duodecime as well as covered flutes, e.g. B. in the organ register "Überblasend Gedackt".