Lumatone mapping for 39edo: Difference between revisions

== Augmented + Immunity ==

 

[[Bryan Deister]] has used a [[Porcupine]]-inspired layout for [[39edo]], as demonstrated in [https://www.youtube.com/watch?v=XLRaG_pBN7k&lc=UgwfjZwncsryQjeNUg14AaABAg.AHVkw8aNSEGAHZU_J2qOPM ''39edo jam''] (2025). To take advantage of the fact that 39edo is at the intersection of [[Augmented]] and [[Immunity]], the rightward generator is 5\39, half of a [[6/5]] minor third as [[12/11]] ~ [[11/10]] (but much closer to 12/11). This enables a MODMOS derived from [[1L 6s]] by shrinking the large step from 9\39 to 8\39 and expanding one of the small steps from 5\39 to 6\39, to enable chords such as 12/11 (somewhat sharp, at 5\39) - 6/5 (slightly flat, at 10\39) - [[11/8]] (near-just, at 18\39) - [[3/2]] (mildly sharp, 23\39) - [[18/11]] (moderately sharp, at 28\39) - [[9/5]] (near-just, at 33\39). Playing this chord uses almost the same geometry of depressed keys as that for playing a diatonic scale in a diatonic mapping (but has a very different sound effect), save when proceeding to the next octave. The range is slightly over 6 octaves overall (which slant moderately downwards), but with the first and last octaves missing some notes due to clipping in the upper left and lower right corners of the layout.

The [[Lumatone mapping for Amity]] is also above average at putting good intervals close together, and makes chromatic runs much easier than the previous two layouts.

== Semiquartal (Immunity) ==

The [[Immunity]] mapping gives excellent range, but the resulting [[5L 4s]] scale has a 7:1 step ratio, which makes it very lopsided.