19-limit

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The 19-limit consists of just intonation intervals whose ratios contain no prime factors higher than 19. It is the 8th prime limit and is thus a superset of the 17-limit and a subset of the 23-limit.

The 19-limit is a rank-8 system, and can be modeled in a 7-dimensional lattice, with the primes 3, 5, 7, 11, 13, 17, and 19 represented by each dimension. The prime 2 does not appear in the typical 19-limit lattice because octave equivalence is presumed. If octave equivalence is not presumed, an eighth dimension is need.

Terminology and notation

Intervals of HC19 are relatively clear in terms of their categories. 19/16 is most commonly considered a minor third, as 1-19/16-3/2 is an important tertian chord. The Functional Just System and Helmholtz-Ellis notation agree. However, 19/16 may act as an augmented second in certain cases. This is more complex on its own but may simplify certain combinations with other intervals, especially if 17/16 is considered an augmented unison and/or if 23/16 is considered an augmented fourth. Perhaps most interestingly, Sagittal notation provides an accidental to enharmonically spell intervals of HC19 this way.

Edo approximation

Here is a list of edos with progressively better tunings for 19-limit intervals (decreasing TE error): 72, 94, 103h, 111, 121, 130, 140, 152fg, 159, 161, 183, 190g, 193, 212gh, 217, 243e, 270, 311, 400, 422, 460, 525, 581, 742, 935, 954h and so on.

Here is a list of edos which provides relatively good tunings for 19-limit intervals (TE relative error < 5%): 72, 111, 217, 243e, 270, 282, 311, 354, 364, 373g, 400, 422, 460, 494(h), 525, 540, 581, 597, 624, 643, 653, 692, 718, 742, 764h, 814, 836f, 882, 908, 925, 935, 954h and so on.

Note: wart notation is used to specify the val chosen for the edo. In the above list, "152fg" means taking the second closest approximation of harmonics 13 and 17.

Intervals

Here are all the 21-odd-limit intervals of 19-limit:

Ratio Cents Value Color Name Interval Name
20/19 88.801 19uy1 nuyo 1son small undevicesimal semitone
19/18 93.603 19o2 ino 2nd large undevicesimal semitone
21/19 173.268 19uz2 nuzo 2nd small undevicesimal whole tone
19/17 192.558 19o17u2 nosu 2nd large undevicesimal whole tone, quasi-meantone
22/19 253.805 19u1o2 nulo 2nd undevicesimal second-third
19/16 297.513 19o3 ino 3rd undevicesimal minor third
24/19 404.442 19u3 inu 3rd small undevicesimal major third
19/15 409.244 19og4 nogu 4th large undevicesimal major third
19/14 528.687 19or4 noru 4th undevicesimal acute fourth
26/19 543.015 19u3o4 nutho 4th undevicesimal super fourth
19/13 656.985 19o3u5 nothu 5th undevicesimal subfifth
28/19 671.313 19uz5 nuzo 5th undevicesimal gravefifth
30/19 790.756 19uy5 nuyo 5th small undevicesimal minor sixth
19/12 795.558 19o6 ino 6th large undevicesimal minor sixth
32/19 902.487 19u6 inu 6th undevicesimal major sixth
19/11 946.195 19o1u7 nolu 7th undevicesimal sixth-seventh
34/19 1007.442 19u17o7 nuso 7th small undevicesimal minor seventh
38/21 1026.732 19or7 noru 7th large undevicesimal minor seventh
36/19 1106.397 19u7 inu 7th small undevicesimal major seventh
19/10 1111.199 19og8 nogu 8ve large undevicesimal major seventh

Music

Domin
Joseph Monzo

See also