Major fourth and minor fifth
Inverse | Minor fifth |
---|---|
Name | |
Other names | Eleventh harmonic Paramajor fourth |
Abbreviation | M4 |
Size | |
Semitones | ~5½ |
Interval class | ~5½ |
Just interval | 11:8 |
Cents | |
24-Tone equal temperament | 550 |
Just intonation | 551.32 |
Inverse | Major fourth |
---|---|
Name | |
Other names | Eleventh subharmonic Paraminor fifth |
Abbreviation | m5 |
Size | |
Semitones | ~6½ |
Interval class | ~5½ |
Just interval | 16:11 |
Cents | |
24-Tone equal temperament | 650 |
Just intonation | 648.68 |
In music, the major fourth and minor fifth, also known as the paramajor fourth and paraminor fifth, are intervals from the quarter-tone scale, named by Ivan Wyschnegradsky to describe the tones surrounding the tritone (F♯/G♭) found in the more familiar twelve-tone scale,[1] as shown in the table below:
perfect fourth | (para)major fourth | tritone | (para)minor fifth | perfect fifth | |
---|---|---|---|---|---|
In C: | F | ≊ F | F♯/G♭ | ≊ G | G |
In cents: | 500 | 550 | 600 | 650 | 700 |
Major fourth
[edit]A major fourth (ⓘ) is the interval that lies midway between the perfect fourth (500 cents) and the augmented fourth (600 cents) and is thus 550 cents (F). It inverts to a minor fifth. Wyschnegradsky considered it a good approximation of the eleventh harmonic[1] (11:8 or 551.32 cents).[2] A narrower undecimal major fourth is found at 537 cents (the ratio 15:11). 31 equal temperament has an interval of 542 cents, which lies in between the two types of undecimal major fourth.
The term may also be applied to the "comma-deficient major fourth" (or "chromatic major fourth"[3]), which is the ratio 25:18, or 568.72 cents (F♯).[4]
Minor fifth
[edit]A minor fifth (ⓘ) is the interval midway between the diminished fifth (600 cents) and the perfect fifth (700 cents) and thus 650 cents (G). It inverts to a major fourth. It approximates the eleventh subharmonic (G↓), 16:11 (648.68 cents).
The term may also be applied to the ratio 64:45 (G♭-) or 609.77 cents (ⓘ), formed from the perfect fourth (4/3 = 498.04) and the major semitone (16/15 = 111.73),[3] which is sharp of the G♭ tritone. The "comma-redundant minor fifth" has the ratio 36:25 (G♭), or 631.28 cents, and is formed from two minor thirds.[4] The tridecimal minor fifth (13:9), or tridecimal tritone, is slightly larger at 636.6 cents.
Other
[edit]The term major fourth may also be applied to the follow, as minor fifth may be applied to their inversions (in the sense of augmented and diminished):
- The "comma-deficient major fourth" (or "chromatic major fourth"[3]) is the ratio 25:18, or 568.72 cents (F♯).[4]
- 45:32 (F♯+) or 590.22 cents (ⓘ), formed from the major third (5/4 = 386.31) and the major tone (9/8 = 203.91) or two major tones (9:8) and one minor tone (10:9)[3]
- 729:512 (F♯++) or 611.73 cents (ⓘ), formed from the perfect fourth and the apotome.[3]
See also
[edit]References
[edit]- ^ a b Skinner, Miles Leigh (2007). Toward a Quarter-tone Syntax: Analyses of Selected Works by Blackwood, Haba, Ives, and Wyschnegradsky, p.25. ProQuest. ISBN 9780542998478.
- ^ Benson, Dave (2007-01-01). Music: A Mathematical Offering. Cambridge University Press. p. 370. ISBN 9780521853873.
- ^ a b c d e Richard Mackenzie Bacon (1821). "Manuscript Work of Francesco Bianchl", The Quarterly Musical Magazine and Review, Volume 3, p.56.
- ^ a b c (1832). The Edinburgh Encyclopaedia, Volume 9, p.249. Joseph Parker. [ISBN unspecified]