3edt: Difference between revisions
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{{ED intro}} | |||
== | == Theory == | ||
3edt can be thought of as [[2edo]] with the 3/1 made just, by [[Stretched tuning|stretching]] the octave by 67.97{{c}}. | |||
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>. | |||
[[ | === Harmonics === | ||
[[ | {{Harmonics in equal|3|3|1|columns=15}} | ||
== Relationship to octave temperaments == | |||
One step of 3edt can represent the generator to any rank-2 octavated temperament which takes 3 generators to reach the 3rd harmonic. These are: | |||
=== Simple octave temperaments === | |||
* [[Liese]] | |||
* [[Triton]] | |||
* [[Alphatricot]] | |||
=== Fractional-octave temperaments === | |||
* [[Augene]], [[augmented (temperament)|augmented]], [[august]] – can be seen as a superset of [[3edo]] and 3edt | |||
* [[Soviet ferris wheel]] – [[20edo]] and 3edt | |||
* [[Akjayland]] – [[21edo]] and 3edt | |||
* [[Oganesson]] – [[118edo]] and 3edt | |||
== See also == | |||
* [[Alpha, beta, and gamma family of equal divisions]] | |||