Build a 12-bit mode mask from a list of semitone offsets above the root.
Bit 0 (the root) is always set, enforcing the KeyScale invariant that the root is a scale tone even when the offset list omits 0.
KeyScale
Build a 12-bit mode mask from a list of semitone offsets above the root.
Bit 0 (the root) is always set, enforcing the
KeyScaleinvariant that the root is a scale tone even when the offset list omits 0.