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,
Hexatonic scale Others have referred to it as the "Promethean chord". Since blue notes are alternate inflections, strictly speaking there can be no one blues scale, but the scale most commonly called "the blues scale" comprises a flatted seventh blue note, a flatted third blue note, and a flatted fifth blue note along with other pitches derived from the minor pentatonic scale: C E F G G B C. The tritone scale, C D E G G() B, is enharmonically equivalent to the Petrushka chord, C C E F G A. The "two-semitone tritone scale", C D D F G A, is