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


== Theory ==
== Theory ==
3edt can be thought of as [[2edo]] with the 3/1 made just, by [[Stretched tuning|stretching]] the octave by 67.97{{c}}.


3edt can be thought of as [[2edo]] with the 3/1 made just, by [[Stretched tuning|stretching]] the octave by 67.97 cents.
Despite its small size, 3edt has an excellent approximation to the 13th harmonic: 7 steps of 3edt is only 2.63{{c}} flat of 13/1. One step of 3edt has two good 13-limit [[Nearest just interval|rational approximations]], [[13/9]] and 75/52, both which are [[convergent]]s. 3edt thus tempers out {{nowrap|(13/9)<sup>3</sup> / (3/1) {{=}} [[2197/2187]]}}, the threedie, and  {{nowrap|(75/52)<sup>3</sup> / (3/1) {{=}} [[140625/140608]]}}, the catasma. The good approximation for 13/9 and 75/52 also implies a good approximation for 25/4, or ([[5/2]])<sup>2</sup>.
 
Despite its small size, 3edt has an excellent approximation to the 13th harmonic: 7 steps of 3edt is only 2.63 cents flat of 13/1. This is reinforced by 3edt having two good 13-limit [[Nearest just interval|rational approximations]], [[13/9]] and 75/52, both which are [[convergent]]s. 3edt thus tempers out (13/9)<sup>3</sup> / (3/1) = [[2197/2187]], the threedie, and  (75/52)<sup>3</sup> / (3/1) = [[140625/140608]], the catasma.


=== Harmonics ===
=== Harmonics ===
{{Harmonics in equal|3|3|1}}
{{Harmonics in equal|3|3|1|columns=15}}


== Relationship to octave temperaments ==
== Relationship to octave temperaments ==
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* [[Liese]]
* [[Liese]]
* [[Triton]]
* [[Triton]]
* [[Tricot]]
* [[Alphatricot]]


=== Fractional-octave temperaments ===
=== Fractional-octave temperaments ===
* [[Augene]], [[augmented]], [[august]] - can be seen as a superset of [[3edo]] and 3edt
* [[Augene]], [[augmented (temperament)|augmented]], [[august]] can be seen as a superset of [[3edo]] and 3edt
* [[Soviet ferris wheel]] - [[20edo]] and 3edt
* [[Soviet ferris wheel]] [[20edo]] and 3edt
* [[Akjayland]] - [[21edo]] and 3edt
* [[Akjayland]] [[21edo]] and 3edt
* [[Oganesson]] - [[118edo]] and 3edt
* [[Oganesson]] [[118edo]] and 3edt
 
== See also ==
* [[Alpha, beta, and gamma family of equal divisions]]