Quarter-comma meantone each kind, a perfect fifth of meantone contains four diatonic and three chromatic semitones, and an octave seven diatonic and five chromatic semitones, it follows that: Thus, in Pythagorean tuning, where sequences of just fifths (frequency ratio 3:2) and octaves are used to produce the other intervals, a whole tone is and a major third is An interval of a seventeenth, consisting of sixteen diatonic and twelve chromatic semitones, such as the interval from D to F, can be equivalently obtained using either This large interval of a seventeenth contains staff positions. In Pythagorean tuning, the size of a seventeenth
Regular tuning and temperament itself and its sharpened version, the chromatic semitone, is 7"f" − 4 of an octave. The common size of the intervals C–D, D–E, F–G, G–A and A–B, the whole tone, is the sum of the diatonic and chromatic semitones, or 2"f" − 1 of an octave. The diatonic semitone is larger than, smaller than, or equal to, the chromatic semitone according as "f" is less than, greater than, or equal to, 7/12. In the last case, the diatonic and chromatic semitones are both 1/12 of an octave, exactly half the size of a tone, and the tuning is 12-tone equal