Lumatone mapping for 49edo: Difference between revisions

The most efficient mapping for [[49edo]], having a range of 5¼ octaves (which slope down moderately) with no missed notes and no repeated notes, is [[Bryan Deister]]'s [[4L 3s]] (10:3 step ratio) mapping that functions for both a rank-2 or rank-3 [[archipelago]]-related temperament and [[catalan]] temperament, demonstrated in [https://www.youtube.com/shorts/34w7euOF-Ss ''49edo improv''] (2026). The rank-2 archipelago-related temperament (which is not currently on the archipelago page) uses one key right (10\49) as a slightly sharp tridecimal semifourth ~[[15/13]] (in the 49f val) for its generator; two of them make the fairly flat fourth ~[[4/3]]; four of them make the sharp septimal minor seventh ~[[7/4]]; six of them (after octave reduction) make a slightly sharp septimal minor third ~[[7/6]]; thirteen of them (after more octave reduction) make a near-just undecimal minor sixth ~[[11/7]]; and fourteen of them make a sharp classic minor seventh ~[[9/5]]. Although this is a respectable list of intervals, the unmodified rank-2 version of the temperament does not make a very good [[MOS]] scale — instead it makes for scales in which the small interval is only 1\49. Therefore, for facility in making scales, including the aforementioned 4L 3s, a second generator is needed (thus elevating this to a rank-3 temperament that tempers out [[364/363]], [[540/539]], and [[847/845]]); that generator uses one key down-right (3\49) as the slightly sharp classic chromatic semitone ~[[25/24]], which 49edo uses here more like a diatonic semitone (although the actual 49edo diatonic semitone is only 2\49). Catalan uses one key right plus one key down-right (13\49) as a slightly sharp classic minor third for its generator; two of them make a very flat Axirabian paraminor fifth ~[[16/11]]; four of them (after octave reduction) make a slightly sharp classic chromatic semitone ~[[25/24]]; five of them make a mildly sharp classic major third ~[[5/4]]; six of them make a sharp fifth ~[[3/2]]; seven of them make a sharp classic minor seventh ~[[9/5]]; eight of them (after more octave-reduction) make a mildly flat undecimal neutral second ~[[12/11]]; and ten of them make a near-just undecimal minor sixth ~[[11/7]]. Catalan does not need a second generator to produce usable MOS scales, including the aforementioned 4L 3s.

{{Lumatone EDO mapping|n=49|start=4|xstep=10|ystep=-7}}

== Machine ==

It is possible to get closer to level octaves for [[49edo]] with a slight gain in practical efficiency (having three repeated notes in each octave, but no non-contiguous notes in the lower left and upper right corners compared to the the archipelago + catalan mapping) with a machine scale ([[5L 1s]], with a 9:4 step ratio). [[Bryan Deister]] has demonstrated this in [[Bryan Deister]]'s [https://www.youtube.com/shorts/_yNrDI6nS1I ''49edo riff''] (2026). This mapping has a contiguous range of 5⅓ octaves; and the repeated notes may provide a bit of assistance with mitigation of vertical wraparounds. This mapping uses 9\49 (one key right) as its generator, which functions as a very flat septimal major second ~[[8/7]], a very sharp (and inconsistently-mapped) Pythagorean major second ~[[9/8]], and (much more accurately) a near-just undecimal acute whole tone ~[[25/22]] (both the Archytas comma [[64/63]] and the valinorsma [[176/175]] are tempered out). Two of them make a somewhat sharp septimal major third ~[[9/7]]; four of them make a slightly sharp classic major sixth ~[[5/3]]; seven of them (after octave reduction) make a somewhat flat undecimal neutral third ~[[11/9]]; eight of them make a very sharp undecimal major fourth ~[[11/8]]; and nine of them make a near-just undecimal minor sixth ~[[11/7]]. Thus, this mapping favors mostly xenharmonic intervals.

{{Lumatone EDO mapping|n=49|start=4|xstep=9|ystep=-5}}

{{Navbox Lumatone}}