Deeptone

Deeptone or tragicomical is a 5-limit temperament that tempers out the comma 177147/163840. It is generated by a fifth (~3/2), which is typically sharper than in 7edo but flatter than in flattone or flattertone (approximately 686-691 ¢). The ~5/4 is reached by eleven fifths octave-reduced, which is an augmented third (C-E#). A characteristic feature of deeptone is that the syntonic comma is tuned negative, represented by a diminished unison (C-Cb). This means that ~81/64 is a submajor third, tuned flatter than ~5/4, and ~32/27 is a supraminor third, tuned sharper than ~6/5. It has high error because of its flat tuning of 3/2, although the well-known Mavila temperament has a 3/2 that is much flatter still. 4 EDOs support Deeptone in their patent val (7edo, 33edo, 40edo, and 47edo), and additionally there is the near-patent val 54b-edo.

See Syntonic–chromatic equivalence continuum#Deeptone a.k.a. tragicomical for technical data.

Deeptone[7] major scale in 40edo.

Etymology

Deeptone was given by CompactStar in 2023, referring to the temperament featuring fifths even flatter than flattone. Tragicomical was allegedly given by groundfault no later than 2023.

Extensions

Deeptone has an accurate 13/8, represented by the interval notated as a minor sixth, so it is very plausible to have a 2.3.5.13 subgroup extension tempering out both 177147/163840 and 1053/1024 (the tridecimal comma). This also gives a more simple interpretation of Deeptone's major and minor thirds as tridecimal neutral thirds 16/13 and 39/32 respectively. Tuning this Deeptone extension in 40edo results in essentially perfect tuning of 13/8 and 16/13, which is inherited from 10edo.

Scales

When properly tuned, Deeptone features MOS scales of the families 2L 3s, 5L 2s, 7L 5s, 7L 12s, and 7L 19s. Another important scale, intermediate between the 7L 5s and 7L 12s scales, is the "Deeptone[14]" non-MOS scale. This scale is notable for being the smallest Deeptone scale that is generally "complete" for 5-limit purposes (as noted by groundfault) since Deeptone[12] has a paucity of 5-limit triads. Deeptone[14] is essentially just two interlaced Deeptone[7] diatonic scales with one of them being offset by an augmented unison above the other.

Interval chain

In the following table, prime harmonics are labeled in bold.

#	Notation			Cents*	Approximate ratios (5-limit)	Aditional ratios in 2.3.5.13 extension
0	perfect unison	P1	C	0.0	1/1	1	perfect fifth	P5	G	689.879	3/2	2	major second	M2	D	689.879	3/2

* In 5-limit CTE tuning

Notes

Todo: expand