Blackwood temperament modal harmony (in 15edo): Difference between revisions
mNo edit summary Tags: Mobile edit Mobile web edit |
mNo edit summary Tags: Mobile edit Mobile web edit |
||
| Line 1: | Line 1: | ||
Blacksmith[10] in [[15edo|15edo]] refers to the 10-note symmetric 5L5s [[MOSScales|MOS]] scale in 15edo, which has two modes: 2 1 2 1 2 1 2 1 2 1 and 1 2 1 2 1 2 1 2 1 2. It can be thought of as a 5-limit temperament tempering out 256/243 (the Pythagorean diatonic semitone), a 7-limit temperament tempering out 28/27 and 49/48, and an 11-limit temperament tempering out 28/27, 49/48, and 55/54 (though in 15edo 121/120 and 100/99 are both tempered out as well, making the tuning identical to Ferrier and the unnamed 5c&15 temperament). In 15edo it has a period of 240 cents (5 periods per octave) and a generator of 80 or 160 cents (though it is more commonly described as having a generator of 400 cents). | |||
==Important features of Blacksmith[10] in 15edo== | |||
<ul><li>As an 11-limit temperament, Blacksmith is extremely simple and efficient, and while it does fairly high damage to many ratios of 3 and 9, it does a very acceptable job of approximating most ratios of 5, 7, and 11. 9/8, 7/6, 11/9, 4/3, and their octave inversions are the most heavily-damaged, but 6/5, 12/11, and their octave inversions are tuned with good to tolerable accuracy.</li><li>Blacksmith[10] has the most 5-odd-limit consonant triads it is possible to have in a 10-note 5-limit scale.</li><li>Because it is a 10-note scale with a period of 1/5 of an octave, any arbitrary harmony will occur either 5 or 10 times within the 10-note scale, and for otonal harmonies consisting of three or more notes, the utonal counterpart of the harmony will also occur either 5 or 10 times within the scale; this is a property that is only held by other scales with 5 periods per octave.</li><li>Blacksmith[10] is also a "mode of limited transposition" like the Diminished and Augmented scales in 12edo: since the scale is built by applying the generator only a single time within each period, the scale has only two modes.</li><li>Another way to think about Blacksmith[10] is as a superposition of seven 7-note 5-limit Fokker blocks, representing untempered variations of the diatonic modes, built on a single tonic (more on this below).</li></ul> | |||
[[file:blacksmith_lattice_igs.png|frame|none|Blacksmith lattice]] | |||
==Interval Classes in Blacksmith[10]== | |||
{| class="wikitable" | |||
|- | |||
| | Step of 15edo | |||
| | Cent Value | |||
| | Interval Class | |||
| | Guitar Notation | |||
| | Decimal Notation | |||
| | Approximated Ratios | |||
| | Pseudo-Diatonic Category | |||
|- | |||
| | 0 | |||
| | 0 | |||
| | Unison | |||
| | E | |||
| | 1 | |||
| | 1/1 | |||
| | Unison | |||
|- | |||
| | 1 | |||
| | 80 | |||
| | Minor 2nd, Augmented Unison* | |||
| | E#, Gbb | |||
| | 2b, 1# | |||
| | 16/15, 21/20, 22/21, 25/24 | |||
| | Minor 2nd | |||
|- | |||
| | 2 | |||
| | 160 | |||
| | Major 2nd, Diminished 3rd | |||
| | Gb, Ex | |||
| | 2, 3b | |||
| | 10/9, 11/10, 12/11, 15/14 | |||
| | Flat Major 2nd | |||
|- | |||
| | 3 | |||
| | 240 | |||
| | Perfect 3rd, Augmented 2nd, Diminished 4th | |||
| | G | |||
| | 3, 2#, 4bb | |||
| | 7/6, 8/7, 9/8 | |||
| | Major 2nd/Subminor 3rd | |||
|- | |||
| | 4 | |||
| | 320 | |||
| | Minor 4th, Augmented 3rd | |||
| | G#, Abb | |||
| | 4b, 3# | |||
| | 6/5, 11/9 | |||
| | Minor 3rd | |||
|- | |||
| | 5 | |||
| | 400 | |||
| | Major 4th, Diminished 5th | |||
| | Ab, Gx | |||
| | 4, 5b | |||
| | 5/4, 14/11, | |||
| | Major 3rd | |||
|- | |||
| | 6 | |||
| | 480 | |||
| | Perfect 5th, Augmented 4th, Diminished 6th | |||
| | A | |||
| | 5, 4#, 6bb | |||
| | 4/3, 21/16, 9/7 | |||
| | Perfect Fourth | |||
|- | |||
| | 7 | |||
| | 560 | |||
| | Minor 6th, Augmented 5th | |||
| | A#, Bbb | |||
| | 6b, 5# | |||
| | 7/5, 11/8, | |||
| | Augmented Fourth | |||
|- | |||
| | 8 | |||
| | 640 | |||
| | Major 6th, Diminished 7th | |||
| | Bb, Ax | |||
| | 6, 7b | |||
| | 10/7, 16/11 | |||
| | Diminished 5th | |||
|- | |||
| | 9 | |||
| | 720 | |||
| | Perfect 7th, Augmented 6th, Diminished 8th | |||
| | B | |||
| | 7, 6#, 8bb | |||
| | 3/2, 32/21, 14/9 | |||
| | Perfect Fifth | |||
|- | |||
| | 10 | |||
| | 800 | |||
| | Minor 8th, Augmented 7th | |||
| | B#, Dbb | |||
| | 8b, 7# | |||
| | 8/5, 11/7, | |||
| | Minor 6th | |||
|- | |||
| | 11 | |||
| | 880 | |||
| | Major 8th, Diminished 9th | |||
| | Db, Bx | |||
| | 8, 9b | |||
| | 5/3, 18/11 | |||
| | Major 6th | |||
|- | |||
| | 12 | |||
| | 960 | |||
| | Perfect 9th, Augmented 8th, Diminished 10th | |||
| | D | |||
| | 9, 8#, 0bb | |||
| | 12/7, 7/4, 16/9 | |||
| | Minor 7th/Supermajor 6th | |||
|- | |||
| | 13 | |||
| | 1040 | |||
| | Minor 10th, Augmented 9th | |||
| | D#, Ebb | |||
| | 0b, 9# | |||
| | 9/5, 20/11, 11/6, 28/15 | |||
| | Sharp Minor 7th | |||
|- | |||
| | 14 | |||
| | 1120 | |||
| | Major 10th, Diminished Undecave | |||
| | Eb, Dx | |||
| | 0, 1b | |||
| | 15/8, 40/21, 48/25 | |||
| | Major 7th | |||
|- | |||
| | 15 | |||
| | 1200 | |||
| | Undecave ("Octave") | |||
| | E | |||
| | 1 | |||
| | 2/1 | |||
| | Octave | |||
|} | |||
*Augmented and diminished intervals do not occur in the 10-note MOS scale, but can occur in chromatically-altered MODMOSs. | |||
=Chords of Blacksmith[10]= | =Chords of Blacksmith[10]= | ||