View source for 4edt

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

== Theory ==
4edt fails to approximate a lot of low prime harmonics well—the first prime harmonic that is approximated by 4edt within 10 cents is 47. (Compare this to [[3edt]], which has the 13th harmonic, and [[5edt]], which has the 5th harmonic.) Nevertheless, in terms of [[convergent]]s, 4edt manages to accurately approximate [[25/19]] with one step, and a less accurate [[16/7]] with three steps (hence [[21/16]] with one step). However, it is not until edts with further multiples of 4 (i.e. [[8edt]], [[12edt]], etc.) that these intervals see practical use.

4edt can be viewed as a "collapsed" version of the [[Bohlen–Pierce]] [[4L 5s (3/1-equivalent)|lambda scale]], analogous to how 5edo is a [[collapsed]] version of the [[diatonic]] scale.  While the approximation for the 5th and 7th harmonics by 4edt may seem excessively vague (or even impossibly vague, as some might say), they are nevertheless categorically important to the perception of the scale{{clarify}}. Given the width of the "scale", 4edt can even be perceived as within the modal logic of Bohlen-Pierce harmony. However, it is doubtful that this scale could receive much melodic treatment, and is more useful as an abstract harmonic entity, either to skeletonize BP harmony, or serving as a subset of scales like [[8edt]].

=== Harmonics ===
{{Harmonics in equal|4|3|1|columns=15}}

=== Approximation of intervals ===
{| class="wikitable right-all left-4 left-5"
|-
! Steps
! Cents
! [[Hekt]]s
! Corresponding<br>JI intervals
! Comments
|-
| 0
| 0.0000
| 0
| [[1/1]]
| perfect unison
|-
| 1
| 475.4888
| 325
| [[17/13]], [[21/16]], [[25/19]], 33/25
| 
|-
| 2
| 950.9775
| 650
| [[19/11]], 45/26, [[26/15]], (85/49), 33/19
| one step of [[2edt]]
|-
| 3
| 1426.4663
| 975
| 25/11, 57/25, [[16/7]], 39/17
|
|-
| 4
| 1901.9550
| 1300
| [[3/1]]
| [[3/2|just perfect fifth]] plus an octave
|}

== Related regular temperaments ==
4EDT is a generator of the [[Vulture family|vulture temperament]], which tempers out 10485760000/10460353203 in the 5-limit.

[[Category:Macrotonal]]