Leapday: Difference between revisions

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Rework as a no-19 23-limit temp
Interval chain: +17-limit + 23 intervals
Line 10: Line 10:


== Interval chain ==
== Interval chain ==
In the following table, odd harmonics 1–21 are in '''bold'''.  
In the following table, odd harmonics 1–23 are in '''bold'''.  


{| class="wikitable center-1 right-2"
{| class="wikitable center-1 right-2"
! #
! rowspan="2" | #
! Cents*
! rowspan="2" | Cents*
! Approximate Ratios
! colspan="2" | Approximate ratios
|-
! 13-limit
! 17-limit add-23 extension
|-
|-
| 0
| 0
| 0.0
| 0.0
| '''1/1'''
| '''1/1'''
|
|-
|-
| 1
| 1
| 704.3
| 704.3
| '''3/2'''
| '''3/2'''
|
|-
|-
| 2
| 2
| 208.6
| 208.6
| '''9/8'''
| '''9/8'''
| 17/15, 26/23
|-
|-
| 3
| 3
| 912.9
| 912.9
| 22/13, 27/16
| 22/13, 27/16
| 17/10
|-
|-
| 4
| 4
| 417.2
| 417.2
| 14/11
| 14/11
| 23/18
|-
|-
| 5
| 5
| 1121.5
| 1121.5
| 21/11, 40/21
| 21/11, 40/21
| 23/12, 44/23
|-
|-
| 6
| 6
| 625.8
| 625.8
| 10/7, 13/9
| 10/7, 13/9
| '''23/16'''
|-
|-
| 7
| 7
| 130.0
| 130.0
| 13/12, 14/13, 15/14
| 13/12, 14/13, 15/14
|
|-
|-
| 8
| 8
| 834.3
| 834.3
| '''13/8''', 21/13
| '''13/8''', 21/13
| 34/21
|-
|-
| 9
| 9
| 338.6
| 338.6
| 11/9, 39/32, 40/33
| 11/9, 39/32, 40/33
| 17/14, 28/23
|-
|-
| 10
| 10
| 1042.9
| 1042.9
| 11/6, 20/11
| 11/6, 20/11
| 42/23
|-
|-
| 11
| 11
| 547.2
| 547.2
| '''11/8''', 15/11
| '''11/8''', 15/11
|
|-
|-
| 12
| 12
| 51.5
| 51.5
| 28/27, 33/32, 40/39, 45/44
| 28/27, 33/32, 40/39, 45/44
| 34/33, 35/34
|-
|-
| 13
| 13
| 755.8
| 755.8
| 14/9, 20/13
| 14/9, 20/13
| 17/11
|-
|-
| 14
| 14
| 260.1
| 260.1
| 7/6, 15/13
| 7/6, 15/13
|
|-
|-
| 15
| 15
| 964.4
| 964.4
| '''7/4'''
| '''7/4'''
| 40/23
|-
|-
| 16
| 16
| 468.7
| 468.7
| '''21/16'''
| '''21/16'''
| 17/13, 30/23
|-
|-
| 17
| 17
| 1173.0
| 1173.0
| 63/32, 160/81
| 63/32, 160/81
| 45/23, 51/26
|-
|-
| 18
| 18
| 677.3
| 677.3
| 40/27
| 40/27
| 34/23
|-
|-
| 19
| 19
| 181.6
| 181.6
| 10/9
| 10/9
|
|-
|-
| 20
| 20
| 885.8
| 885.8
| 5/3
| 5/3
|
|-
|-
| 21
| 21
| 390.1
| 390.1
| '''5/4'''
| '''5/4'''
|
|-
|-
| 22
| 22
| 1094.4
| 1094.4
| '''15/8'''
| '''15/8'''
| 17/9
|-
|-
| 23
| 23
| 598.7
| 598.7
| 45/32
| 45/32
| 17/12
|}
|}
<nowiki />* In 13-limit CTE tuning
<nowiki />* In 13-limit CTE tuning

Revision as of 14:23, 23 October 2024

Not to be confused with calendar-based scales such as those in 293edo, 400edo, 353edo or Irvian mode.

Leapday is a regular temperament for the 7-, 11-, 13-, 17-, and no-19 23-limit. It is based on the chain of fifths, but here, the fifth is tuned slightly sharp of just so that 6 fifths give 23/16, 8 fifths give 13/8, 11 fifths give 11/8, 15 fifths give 7/4, 21 fifths give 5/4, and 24 fifths make 17/16. Equivalently, the fifth in leapday is ~2.3 cents sharp of 3/2 (approximately 704 ¢), so that 23/16 is represented by an augmented fourth (C–F♯), 13/8 is represented by an augmented fifth (C–G♯), 11/8 is represented by an augmented third (C–E♯), the harmonic seventh is represented by a doubly augmented fifth (C–G𝄪), the classical major third is represented by a triply augmented unison (C–C𝄪♯), and 17/16 is represented by an octave-reduced triply augmented sixth (C–A𝄪♯).

The no-5's 13-limit version of leapday, known as leapfrog, is notable as tempering parapythic (a rank-3 temperament of the 2.3.7.11.13 subgroup) to rank 2 by finding ~13/8 at (~9/8)4, that is, by tempering out the tetris comma, and is a good combination of simplicity and accuracy, as prime 5 is complex and the canonical mapping for prime 19 is fairly off.

Leapday was named by Herman Miller in 2004[1][2].

See Hemifamity temperaments #Leapday or No-fives subgroup temperaments #Leapfrog for more technical data.

Interval chain

In the following table, odd harmonics 1–23 are in bold.

# Cents* Approximate ratios
13-limit 17-limit add-23 extension
0 0.0 1/1
1 704.3 3/2
2 208.6 9/8 17/15, 26/23
3 912.9 22/13, 27/16 17/10
4 417.2 14/11 23/18
5 1121.5 21/11, 40/21 23/12, 44/23
6 625.8 10/7, 13/9 23/16
7 130.0 13/12, 14/13, 15/14
8 834.3 13/8, 21/13 34/21
9 338.6 11/9, 39/32, 40/33 17/14, 28/23
10 1042.9 11/6, 20/11 42/23
11 547.2 11/8, 15/11
12 51.5 28/27, 33/32, 40/39, 45/44 34/33, 35/34
13 755.8 14/9, 20/13 17/11
14 260.1 7/6, 15/13
15 964.4 7/4 40/23
16 468.7 21/16 17/13, 30/23
17 1173.0 63/32, 160/81 45/23, 51/26
18 677.3 40/27 34/23
19 181.6 10/9
20 885.8 5/3
21 390.1 5/4
22 1094.4 15/8 17/9
23 598.7 45/32 17/12

* In 13-limit CTE tuning

Tunings

Tuning spectrum

This spectrum assumes 19-limit leapday.

Edo
generator
Eigenmonzo
(unchanged-interval)
*
Generator (¢) Comments
19/16 700.829
19/12 701.110
19/18 701.279
3/2 701.955
24\41 702.439 41cc… val, lower bound of 5-odd-limit diamond monotone
15/14 702.778
7/5 702.915
21/20 703.107
15/11 703.359
15/13 703.410
17\29 703.448 29g val, lower bound of 7-, 9-, 11-, 13-, and 15-odd-limit diamond monotone
11/10 703.500
13/10 703.522
13/11 703.597
19/15 703.630
19/10 703.700
21/13 703.782
19/11 703.843
21/19 703.856
21/11 703.893
19/13 703.910
19/14 703.962
19/17 703.979 19- and 21-odd-limit minimax
44\75 704.000 75dfgh val
15/8 704.012
17/14 704.014
17/13 704.027
13/7 704.043
5/4 704.110 5-odd-limit minimax
17/11 704.126
71\121 704.132 121defgh val
5/3 704.218 7-, 15- and 17-odd-limit minimax
21/17 704.272
9/5 704.337 9-, 11- and 13-odd-limit minimax
27\46 704.348
17/16 704.373
11/7 704.377
21/16 704.424
17/12 704.478
7/4 704.588
17/9 704.593
11/8 704.665
37\63 704.762 63ch val
7/6 704.776
11/6 704.936
9/7 704.994
13/8 705.066
11/9 705.268
13/12 705.510
10\17 705.882 17cg val, upper bound of 5-, 7-, 9-, 11-, 13-, and 15-odd-limit diamond monotone
13/9 706.103
17/10 706.214
17/15 708.343

* Besides the octave

Notes