Shift a pitch by scale degrees along the key's ladder of scale tones.
A pitch between two scale tones keeps its distance above the one below it, so
a chromatic passing note is still a chromatic passing note after the shift,
and a shift of no degrees returns the pitch untouched: a step up the C-major
ladder answers C# with D#, not with D.
Layer-internal. It is what transposeDiatonic and a tonal imitation both
count along, so the two answer the same shift the same way; a caller reaches
it through either of them.
Shift a pitch by scale degrees along the key's ladder of scale tones.
A pitch between two scale tones keeps its distance above the one below it, so a chromatic passing note is still a chromatic passing note after the shift, and a shift of no degrees returns the pitch untouched: a step up the C-major ladder answers C# with D#, not with D.
Layer-internal. It is what
transposeDiatonicand a tonal imitation both count along, so the two answer the same shift the same way; a caller reaches it through either of them.