I am currently working out some SATB composition and I am wondering a bit about the alto-tenor part. There is fourth to fifth in parallel motion in the first measure. Is this permitted in strict SATB? Will it be considered consecutive fifths if the G in the first chord is moved up one octave?
1 Answer
It's not really parallel motion as the interval changes. It is similar motion. However it's also moving by non-contrary motion into a perfect interval which is usually avoided in strict counterpoint. Between outer voices, moving by similar motion to a perfect interval (like an octave or fifth) can make is sound like one voice dropped out; it's usually avoided. Between inner voices, the effect is not so marked.