MOS substitution

MOS substitution is a procedure for obtaining a ternary (3 step sizes) scale from two MOS patterns. It consists of taking one MOS pattern (called the template MOS), choosing a step size, and overwriting all instances of that step size using the step pattern of another MOS pattern (called the filling MOS). Unlike MV3 scales, a MOS substitution scale may have any combination of step sizes.

Examples

Many familiar ternary scales can be constructed as MOS substitutions.

LMsLMLs <- LLsLLLs x LMLML, LssLsLs x MsMs, sMssMss x LsLLs

LLmLLLs <- LLsLLLs x ms

LMsLM <- LLsLL x LMLM

The three standard diaslen scale patterns, denoted 4sL (LsLsLmLsLsm), 4sC (LmLsLsLmLss), and 4sR (LsLmLsLsLms), may be constructed via MOS substitution, giving generator sequences for the three scales:

diaslen scales as MOS substitution scales

chirality	filling MOS	step pattern		generator sequence
		template MOS:	LXLXLXLXLXX	intvl. class of gen.:	2-steps
4sC	mssmss	LmLsLsLmLss		GS(L+m, L+s, L+s)
4sR	smssms	LsLmLsLsLms		GS(L+s, L+m, L+s)
4sL	ssmssm	LsLsLmLsLsm		GS(L+s, L+s, L+m)