Marvel

Revision as of 09:42, 15 January 2025 by FloraC (talk | contribs) (Tunings: rework: this analysis is so at odds with everyone else's, as we've long found 197- and 240edo to be optimal edo tunings in the 7-limit, which is very well documented. The idea of not targeting 7-odd-limit intervals in favor of complex 5-limit intervals is very sus; the facts about 53edo and 84edo are also wrong, with 125edo missing, and the constraint of consistency is so arbitrary that it seems to be there just to single out the edos you like)

Marvel is the rank-3 temperament tempering out 225/224, the marvel comma. It has a canonical 11-limit extension adding 385/384 and 540/539 to the comma list.

The temperament was named by Gene Ward Smith in 2002–2003, when the 11-limit version was found first[1][2]. Gene carried it to the 7-limit restriction in 2004[3].

Extending marvel to the 13-limit is not as obvious. While Gene has chosen 351/350 as the canonical extension, hecate, tempering out 325/324 and 729/728, arguably makes more sense as it is closer in tuning[4]. Hecate has a natural extension to the no-17 19-limit, by tempering out 400/399 and 513/512.

See Marvel family #Marvel for technical data.

Interval lattice

Notation

Marvel can be notated the same as 5-limit just intonation since they share the same lattice structure. One way to do this is to take the conventional circle-of-fifths notation with an additional module of accidentals for the 81/80 comma. In this system, 5/4 is a major third, 7/4 an augmented sixth, and 11/8 a double diminished 5th.

Marvel/hecate nomenclature
for selected intervals
Ratio Nominal Example
3/2 Perfect fifth C-G
5/4 Down major third C-vE
7/4 Dudaugmented sixth C-vvA#
11/8 Trup double-diminished fifth C-^3Gbb
13/8 Dup minor sixth C-^^Ab
19/16 Minor third C-Eb

Alternatively, it can be notated the same as full prime-limit just intonation, with a distinct accidental pair for each prime. That makes some intervals more intuitive, at the cost of hiding the structure of marvel tempering. For example, it is customary of the 5/4 to be a major third, and 7/4 to be a minor seventh. As a result, the fact that the 14/9 is a stack of two 5/4's is not revealed, and the related chords can be less convenient.

Chords

Marvel enables essentially tempered chords of marvel, keenanismic, swetismic, and undecimal marvel. Extending the temperament to the 13-limit through 325/324, resulting in hecate, enables chords of marveltwin and squbemic. Hecate hexad is a chord peculiar to this temperament.

Alternative 11-limit extensions give different sets of chords. One notable example, tempering out 441/440, enables prodigy chords.

Scales

Marvel hobbit scales

Undecimal marvel hobbit scales

Other marvel scales

Tunings

The marvel extension hecate has the no-17's 19-limit as its subgroup, and tridecimal marvel, the extension chosen by Gene Ward Smith, is in the 13-limit. They merge in the rank-2 temperament catakleismic, which can be conceptualized as accepting both rank-3 marvel structures simultaneously. One such tuning is excellently given by 125edo. If we are looking for a small edo tuning instead, 53edo and 72edo are also reasonable edo tunings for the full no-17's 19-limit catakleismic, though in 53edo the 11 and 19 are a little off and in 72edo the 13 and 19 are a little off instead; 72edo is positioned better as a full 17-limit marvel system while 53edo is positioned better as a (potentially no-11's) 13-limit marvel system. If we focus on the 11-limit of undecimal marvel (discarding the mapping of 13), 31edo and 41edo are the smallest to clearly succeed, though many accept 41edo's mapping of ~13/8 to the neutral sixth and some accept that mapping for 31edo as contextually usable too.

53edo and 84edo are the smallest edos to tune the supermajor second ~8/7 flat (towards ~256/225), the subminor third ~7/6 sharp (towards ~75/64), the supermajor third ~9/7 flat (towards ~32/25) and the tritone ~7/5 sharp (towards ~45/32), such that every 7-limit 9-odd-limit interval is tuned between itself and the 5-limit interpretation it is separated from by 225/224, though even if you allow overtempering, the only smaller edo to satisfy all of these constraints is 12edo, which is a trivial tuning of it (meaning it is very high-damage owing to conflating many intervals so that the lattice is oversimplified). TE, CTE, CEE and CWE as well as the idea of tempering between pairs of 5- and 7-limit intervals separated by 225/224 all implicate these tuning tendencies of these 7-limit LCJI intervals for optimized 7-limit marvel tunings. Interestingly, 72edo fails some of these constraints, whereas 53edo though satisfying these constraints is obviously undertempered, tuning the intervals closer to the more complex 5-limit interpretations despite that the very point of marvel is to use these intervals for 7-limit consonances. 84edo, another superset of 12edo, is an interesting edo to look at.

Tuning spectrum

This spectrum assumes pure 2 and 7.

Eigenmonzo
(Unchanged-interval)
Fifth
(¢)
Major
Third (¢)
Comments
5/4 698.099 386.314
6/5 700.027 384.386 7-odd-limit minimax
15/11 700.351 384.062
10/9 700.670 383.743 9-odd-limit minimax
11/10 700.885 383.528
15/13 700.916 383.497 15-odd-limit hecate minimax
13/10 701.065 383.348 13-odd-limit hecate minimax
13/11 701.199 383.214
18/13 701.361 383.052
13/12 701.480 382.933
16/13 701.559 382.854
4/3 701.955 382.458
14/11 702.278 382.135
11/8 702.278 382.135
12/11 702.602 381.811

Music

Billy Stiltner
Chris Vaisvil

See also

Notes