Marvel

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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

In the 7-limit, the optimal way such as that taken by TE and derivatives to close out the comma 225/224 is to tune primes 3 and 5 flat, and 2 and 7 sharp. If we tune the octave pure, the other inclinations remain. This indicates that the diminished third ~256/225 should be sharp (towards ~8/7), the augmented second ~75/64 be flat (towards ~7/6), the diminished fourth ~32/25 be sharp (towards ~9/7) and the tritone ~45/32 be flat (towards ~7/5), 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. If we take these as hard constraints, then 53edo and 84edo are the smallest edo tunings to satisfy them, but if overtempering is allowed, many smaller edos are possible, such as 31- and 41edo. Interestingly, 72edo, though very performant as a 7- and 11-limit tuning, is overtempered for some of these constraints, whereas 53edo, though satisfying these constraints, tempers the intervals closer to the more complex 5-limit interpretations, though the 7-limit concordances of the 9-odd-limit still clearly work. 84edo, another superset of 12edo, is an interesting edo to look at for its high performance in large odd-limits. Going up to larger edos, 125-, 166-, 178-, 197-, and 240edo are all great choices with different intonational characteristics.

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.

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