Arcturus hendecatonic notation

Arcturus hendecatonic notation is a notation system for EDTs and no-twos music, developed by CompactStar. It is based on the 2L 9s⟨3/1⟩ MOS scale generated by approximately 5/3. The 5/3 generator connects this MOS to the 3.5 subgroup and (in the soft-hard range) Arcturus temperament, similar to how the diatonic scale is connected to the 3-limit and (in the equalized-basic range) meantone temperament. The preferred generator for a given EDT is the patent val 5/3.

The 9|1 mode of 2L 9s⟨3/1⟩ is represented by 11 naturals CDEFGHJKLAB, and #/b accidentals are used to raise and lower by a chroma (L - s). For relative notation, the TAMNAMS convention of zero-based indices is used. Assuming Arcturus temperament where 7/3 is mapped to the major 8-step, the chord 3:5:7 is notated as C - H - L (P0 - P5 - M8). To notate larger EDTs, Arcturus hendecatonic notation can be combined with ups and downs notation, with ^/v accidentals raising and lowering by 1 EDTstep.

Examples

11edt (equalized):

0	1	2	3 14	5	6	7	8	9	10	11
C	D	E	F	G	H	J	K	L	A	B	C
P0	P1	P2	P3	P4	P5	P6	P7	P8	P9	P10	P11

13edt (Bohlen-Pierce):

0	1	2	3	4	5	6	7	8	9	10	11	12	13
C	Db	D	E	F	G	H	J	Kb	K	L	A	B	C
P0	m1	M1	M2	M3	M4	P5	P6	m7	M7	M8	M9	M10	P11

24edt:

0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
C	C#, Dbb	Db	D	Eb	E	Fb	F	Gb	G	G#, Hb	H	H#, Jb	J	J#, Kbb	Kb	K	Lb	L	Ab	A	Bb	B	B#, Cb	C
P0	A0, d1	m1	M1	m2	M2	m3	M3	m4	M4	A4, d5	P5	A5, d6	P6	A6, d7	m7	M7	m8	M8	m9	M9	m10	M10	A10, d11	P11