SN scale: Difference between revisions

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Each iteration of a) increasing the rank of the scale by 1.
Each iteration of a) increasing the rank of the scale by 1.


An SN scale of rank 2, a 2-SN scale, is a [[MOS scale]]. Accordingly, SN scales are a generalization of MOS scales into arbitrary rank.
An SN scale of rank 2, a 2-SN scale, is a [[MOS scale]]. Accordingly, SN scales are a generalization of MOS scales into arbitrary rank. ETs can be considered to be 1-SN scales, which can be generated by applying a) once, introducing a step of a single degree of the ET.


SN scales are inversionally symmetric / invariant under reversal, and may be uniquely defined by a ''step signature'' - a generalisation of the MOS signature into arbitrary rank.
SN scales are inversionally symmetric / invariant under reversal, and may be uniquely defined by a ''step signature'' - a generalisation of the MOS signature into arbitrary rank.
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The double harmonic scale can be generated by iterating a) three times, introducing first the octave, then the fifth, then the major third, leading to a major seven tetrad, and then applying b) once. It has step signature 2L 1M 4s, and in the symmetric mode, it has step arrangement sLsMsLs.
The double harmonic scale can be generated by iterating a) three times, introducing first the octave, then the fifth, then the major third, leading to a major seven tetrad, and then applying b) once. It has step signature 2L 1M 4s, and in the symmetric mode, it has step arrangement sLsMsLs.


These scales all have a period of an octave - and therefore a) first introduces the interval of an octave. SN scales may have periods other than an octave - the period, along with the rest of the mapping, is arbitrary.
These scales all have a period of an octave - and therefore a) first introduces the interval of an octave, however, the period of a SN scale, and the mapping of any new smallest step introduced, is arbitrary.


SN scales are a subset of [[MOS Cradle Scales]].
SN scales are a subset of [[MOS Cradle Scales]].


SN scales are based on epi-Christoffel words form combinatorics, which generalize finite Sturmian words, which are equivalent to well-formed scales, and equivalently equivalent to MOS scales that are not ''Multi-MOS'' scales, MOS scales of more than one period, typically with a period that divides the octave evenly.
SN scales are based on epi-Christoffel words form combinatorics, which generalize finite Sturmian words, which are equivalent to well-formed scales, and equivalently equivalent to MOS scales that are not ''Multi-MOS'' scales, MOS scales of more than one period, typically with a period that divides the octave evenly.