7-limit tuning

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Harmonic seventh, septimal seventh Harmonic seventh on C.png
Harmonic seventh, septimal seventh
Septimal chromatic semitone on C Septimal chromatic semitone on C.png
Septimal chromatic semitone on C
9/7 major third from C to E. This, "extremely large third", may resemble a neutral third or blue note. Septimal major third on C.png
9/7 major third from C to E 7 upside down.png . This, "extremely large third", may resemble a neutral third or blue note.
Septimal minor third on C Septimal minor third on C.png
Septimal minor third on C

7-limit or septimal tunings and intervals are musical instrument tunings that have a limit of seven: the largest prime factor contained in the interval ratios between pitches is seven. Thus, for example, 50:49 is a 7-limit interval, but 14:11 is not.

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For example, the greater just minor seventh, 9:5 ( Play ) is a 5-limit ratio, the harmonic seventh has the ratio 7:4 and is thus a septimal interval. Similarly, the septimal chromatic semitone, 21:20, is a septimal interval as 21÷7=3. The harmonic seventh is used in the barbershop seventh chord and music. ( Play ) Compositions with septimal tunings include La Monte Young's The Well-Tuned Piano , Ben Johnston's String Quartet No. 4, Lou Harrison's Incidental Music for Corneille's Cinna, and Michael Harrison's Revelation: Music in Pure Intonation.

The Great Highland bagpipe is tuned to a ten-note seven-limit scale: [3] 1:1, 9:8, 5:4, 4:3, 27:20, 3:2, 5:3, 7:4 , 16:9, 9:5.

In the 2nd century Ptolemy described the septimal intervals: 21/20, 7/4, 8/7, 7/6, 9/7, 12/7, 7/5, and 10/7. [4] Archytas of Tarantum is the oldest recorded musicologist to calculate 7-limit tuning systems. Those considering 7 to be consonant include Marin Mersenne, [5] Giuseppe Tartini, Leonhard Euler, François-Joseph Fétis, J. A. Serre, Moritz Hauptmann, Alexander John Ellis, Wilfred Perrett, Max Friedrich Meyer. [4] Those considering 7 to be dissonant include Gioseffo Zarlino, René Descartes, Jean-Philippe Rameau, Hermann von Helmholtz, Arthur von Oettingen, Hugo Riemann, Colin Brown, and Paul Hindemith ("chaos" [6] ). [4]

Lattice and tonality diamond

The 7-limit tonality diamond:

7/4
3/2 7/5
5/4 6/5 7/6
1/1 1/11/11/1
8/5 5/3 12/7
4/3 10/7
8/7

This diamond contains four identities (1, 3, 5, 7 [P8, P5, M3, H7]). Similarly, the 2,3,5,7 pitch lattice contains four identities and thus 3-4 axes, but a potentially infinite number of pitches. LaMonte Young created a lattice containing only identities 3 and 7, thus requiring only two axes, for The Well-Tuned Piano.

Approximation using equal temperament

It is possible to approximate 7-limit music using equal temperament, for example 31-ET.

FractionCentsDegree (31-ET)Name (31-ET)
1/100.0C
8/72316.0D Arabic music notation half sharp.svg or E Doubleflat.svg
7/62676.9D
6/53168.2E
5/438610.0E
4/349812.9F
7/558315.0F
10/761716.0G
3/270218.1G
8/581421.0A
5/388422.8A
12/793324.1A Arabic music notation half sharp.svg or B Doubleflat.svg
7/496925.0A
2/1120031.0C

Ptolemy's Harmonikon

Claudius Ptolemy of Alexandria described several 7-limit tuning systems for the diatonic and chromatic genera. He describes several "soft" (μαλακός) diatonic tunings which all use 7-limit intervals. [7] One, called by Ptolemy the "tonic diatonic," is ascribed to the Pythagorean philosopher and statesman Archytas of Tarentum. It used the following tetrachord: 28:27, 8:7, 9:8. Ptolemy also shares the "soft diatonic" according to peripatetic philosopher Aristoxenus of Tarentum: 20:19, 38:35, 7:6. Ptolemy offers his own "soft diatonic" as the best alternative to Archytas and Aristoxenus, with a tetrachord of: 21:20, 10:9, 8:7.

Ptolemy also describes a "tense chromatic" tuning that utilizes the following tetrachord: 22:21, 12:11, 7:6.

See also

Related Research Articles

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<span class="mw-page-title-main">Semitone</span> Musical interval

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<span class="mw-page-title-main">Quarter tone</span> Musical interval

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In the musical system of ancient Greece, genus is a term used to describe certain classes of intonations of the two movable notes within a tetrachord. The tetrachordal system was inherited by the Latin medieval theory of scales and by the modal theory of Byzantine music; it may have been one source of the later theory of the jins of Arabic music. In addition, Aristoxenus calls some patterns of rhythm "genera".

<span class="mw-page-title-main">Comma (music)</span> Very small interval arising from discrepancies in tuning

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<span class="mw-page-title-main">Septimal comma</span>

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<span class="mw-page-title-main">Diatonic and chromatic</span> Terms in music theory to characterize scales

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<span class="mw-page-title-main">Septimal quarter tone</span>

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<span class="mw-page-title-main">Septimal third tone</span>

A septimal 1/3-tone is an interval with the ratio of 28:27, which is the difference between the perfect fourth and the supermajor third. It is about 62.96 cents wide. The septimal 1/3-tone can be viewed either as a musical interval in its own right, or as a comma; if it is tempered out in a given tuning system, the distinction between these two intervals is lost. The septimal 1/3-tone may be derived from the harmonic series as the interval between the twenty-seventh and twenty-eighth harmonics. It may be considered a diesis.

<span class="mw-page-title-main">Five-limit tuning</span>

Five-limit tuning, 5-limit tuning, or 5-prime-limit tuning (not to be confused with 5-odd-limit tuning), is any system for tuning a musical instrument that obtains the frequency of each note by multiplying the frequency of a given reference note (the base note) by products of integer powers of 2, 3, or 5 (prime numbers limited to 5 or lower), such as 2−3·31·51 = 15/8.

Ptolemy's intense diatonic scale, also known as the Ptolemaic sequence, justly tuned major scale, Ptolemy's tense diatonic scale, or the syntonousdiatonic scale, is a tuning for the diatonic scale proposed by Ptolemy, and corresponding with modern 5-limit just intonation. While Ptolemy is famous for this version of just intonation, its important to realize this was only one of several genera of just, diatonic intonations he describes. He also describes 7-limit "soft" diatonics and an 11-limit "even" diatonic.

Pyknon, sometimes also transliterated as pycnon in the music theory of Antiquity is a structural property of any tetrachord in which a composite of two smaller intervals is less than the remaining (incomposite) interval. The makeup of the pyknon serves to identify the melodic genus and the octave species made by compounding two such tetrachords, and the rules governing the ways in which such compounds may be made centre on the relationships of the two pykna involved.

References

  1. Fonville, John. "Ben Johnston's Extended Just Intonation – A Guide for Interpreters", p. 112, Perspectives of New Music , vol. 29, no. 2 (Summer 1991), pp. 106–137.
  2. Fonville (1991), p. 128.
  3. Benson, Dave (2007). Music: A Mathematical Offering, p. 212. ISBN   9780521853873.
  4. 1 2 3 Partch, Harry (2009). Genesis of a Music: An Account of a Creative Work, Its Roots, and Its Fulfillments, pp. 90–91. ISBN   9780786751006.
  5. Shirlaw, Matthew (1900). Theory of Harmony, p. 32. ISBN   978-1-4510-1534-8.
  6. Hindemith, Paul (1942). Craft of Musical Composition, vol. 1, p. 38. ISBN   0901938300.
  7. Barker, Andrew (1989). Greek Musical Writings: II Harmonic and Acoustic Theory. Cambridge: Cambridge University Press. ISBN   0521616972.