View source for 30edt

{{Infobox ET}}
{{ED intro}}

== Theory ==
30edt is related to [[19edo]], but with the [[3/1]] rather than the [[2/1]] being [[just]], which results in octaves being is [[stretched and compressed tuning|stretched]] by about 4.5715{{cent}}. Like 19edo, 30edt is [[consistent]] to the [[integer-limit|10-integer-limit]].

Because [[19edo]] has the [[3/1|3rd]], [[5/1|5th]], [[7/1|7th]], and [[13/1|13th]] [[harmonic]]s all flat (the latter two very flat), it benefits greatly from octave stretching. 30edt is one possible alternative; at the cost of sharpening the octave, it achieves much better matches to the odd harmonics; the 3 (tritave) is by definition just, the 5 slightly sharp, and the 7 and 13 slightly flat.

While the fifth is closer to just than in 19edo, the fourth is noticeably sharper and less accurate than in 19edo, being close to that of [[26edo]].

=== Harmonics ===
{{Harmonics in equal|30|3|1|intervals=integer}}
{{Harmonics in equal|30|3|1|intervals=integer|columns=12|start=12|collapsed=1|title=Approximation of harmonics in 30edt (continued)}}

=== Subsets and supersets ===
Since 30 factors into primes as 2 × 3 × 5, 30edt has subset edts {{EDs|equave=t| 2, 3, 5, 6, 10, and 15 }}.

== Intervals ==
{| class="wikitable center-all right-2 right-3 left-4"
|-
! rowspan="2" | #
! rowspan="2" | Cents
! rowspan="2" | [[Hekt]]s
! rowspan="2" | Approximate ratios
! colspan="2" | Scale name
|-
! Lambda
! Sigma
|-
| 0
| 0
| 0
| [[1/1]]
| colspan="2" | C
|-
| 1
| 63.4
| 43.3
| [[27/26]], [[28/27]]
| C^/Dbv
| C#/Dbb
|-
| 2
| 126.8
| 86.7
| [[14/13]], [[15/14]], [[16/15]], [[29/27]]
| Db
| Cx/Db
|-
| 3
| 190.2
| 130.0
| [[9/8]], [[10/9]]
| C#
| D
|-
| 4
| 253.6
| 173.3
| [[15/13]]
| C#^/Dv
| D#/Ebb
|-
| 5
| 317.0
| 216.7
| [[6/5]]
| D
| Dx/Eb
|-
| 6
| 380.4
| 260.0
| [[5/4]]
| D^/Ev
| E
|-
| 7
| 443.8
| 303.3
| [[9/7]]
| E
| E#/Fbb
|-
| 8
| 507.2
| 346.7
| [[4/3]]
| E^/Fbv
| Ex/Fb
|-
| 9
| 570.6
| 390.0
| [[7/5]]
| Fb
| F
|-
| 10
| 634.0
| 433.3
| [[13/9]]
| E#
| F#/Gb
|-
| 11
| 697.4
| 476.7
| [[3/2]]
| E#^/Fv
| G
|-
| 12
| 760.8
| 520.0
| [[14/9]]
| F
| G#/Hbb
|-
| 13
| 824.2
| 563.3
| [[8/5]]
| F^/Gv
| Gx/Hb
|-
| 14
| 887.6
| 606.7
| [[5/3]]
| G
| H
|-
| 15
| 951.0
| 650.0
| [[19/11]]
| G^/Hbv
| H#/Jbb
|-
| 16
| 1014.4
| 693.3
| [[9/5]]
| Hb
| Hx/Jb
|-
| 17
| 1077.8
| 736.7
| [[13/7]]
| G#
| J
|-
| 18
| 1141.2
| 780.0
| [[27/14]]
| G#^/Hv
| J#/Kbb
|-
| 19
| 1204.6
| 823.3
| [[2/1]]
| H
| Jx/Kb
|-
| 20
| 1268.0
| 866.7
| [[27/13]]
| H^/Jv
| K
|-
| 21
| 1331.4
| 910.0
| [[28/13]]
| J
| K#/Lb
|-
| 22
| 1394.8
| 953.3
| [[9/4]]
| J^/Av
| L
|-
| 23
| 1458.2
| 996.7
| [[7/3]]
| A
| L#/Abb
|-
| 24
| 1521.6
| 1040.0
| [[12/5]]
| A^/Bbv
| Lx/Ab
|-
| 25
| 1585.0
| 1083.3
| [[5/2]]
| Bb
| A
|-
| 26
| 1648.4
| 1126.7
| [[13/5]]
| A#
| A#/Bbb
|-
| 27
| 1711.8
| 1170.0
| [[8/3]]
| A#^/Bv
| Ax/Bb
|-
| 28
| 1775.2
| 1213.3
| [[14/5]]
| B
|-
| 29
| 1838.6
| 1256.7
| [[26/9]]
| B^/Cv
| B#/Cb
|-
| 30
| 1902.0
| 1300.0
| [[3/1]]
| colspan="2" | C
|}

30edt contains all [[19edo]] intervals within 3/1, all tempered progressively sharper. The accumulation of the 0.241{{c}} sharpening of the unit step relative to 19edo leads to the excellent 6edt approximations of 6/5 and 5/2. Non-redundantly with simpler edts, the 41 degree ~9/2 is only .6615{{c}} flatter than that in 6edo.

30edt also contains all the mos contained in 15edt, being the double of this equal division. Being even, 30edt introduces mos with an even number of periods per tritave such as a {{mos scalesig|6L 6s<3/1>|link=1}} similar to Hexe Dodecatonic. This mos has a period of 1/6 of the tritave and the generator is a single or double step. The major scale is sLsLsLsLsLsL, and the minor scale is LsLsLsLsLsLs. Being a "real" 3/2, the interval of 11 degrees generates an [[unfair]] [[Sigma]] scale of {{mos scalesig|8L 3s<3/1>|link=1}} and the major scale is LLLsLLLsLLs. The sharp 9/7 of 7 degrees, in addition to generating a Lambda mos will generate a {{mos scalesig|4L 9s<3/1>|link=1}} unfair "Superlambda" mos which does not border on being atonal as the 17edt rendition does.

== Music ==
; [[Mason Green]]
* [https://soundcloud.com/mason-l-green/room-full-of-steam-1 ''Room Full Of Steam''] (2018)

; [[Ray Perlner]]
* [https://www.youtube.com/watch?v=fEQ13hzs3fY ''Fugue for Piano in 30EDT Bohlen-Pierce-Stearns{{lbrack}}9{{rbrack}} sLsLssLsL "Dur I"''] (2024)

== See also ==
* [[11edf]] – relative edf
* [[19edo]] – relative edo
* [[49ed6]] – relative ed6
* [[53ed7]] – relative ed7
* [[68ed12]] – relative ed12
* [[93ed30]] – relative ed30

[[Category:Listen]]