Chromatic scale common conception of the chromatic scale before the 13th century was the Pythagorean chromatic scale (). Due to a different tuning technique, the twelve semitones in this scale have two slightly different sizes. Thus, the scale is not perfectly symmetric. Many other tuning systems, developed in the ensuing centuries, share a similar asymmetry. In Pythagorean tuning (3-limit just intonation) the chromatic scale is tuned as follows, with sharps higher than their enharmonic flats: These are 17-EDO Pythagorean tuning approximations. In 5-limit just intonation the chromatic scale, Ptolemy's intense chromatic scale, is as follows, with flats higher than their enharmonic sharps,
Ditonic scale Ditonic scale A ditonic scale is a musical scale or mode with two notes per octave. This is in contrast to a heptatonic (seven-note) scale such as the major scale and minor scale, or a dodecatonic (chromatic 12-note ) scale, both common in modern Western music. Ethnomusicologist Bruno Nettl noted that ditonic scales were common in many parts of the world but often limited to specific music types, such as children's songs, with the exception of some tribal societies. The Cheremis (Mari people) of Russia employ ditonic scales in children's songs, generally with the two notes a minor third apart.