Direct fifths or octaves by leap in both voices · Rules
No pair of voices reaches a perfect fifth or octave with both voices leaping in the same direction. It is allowed when the same chord only changes position and, in V → I, with the leading tone falling to the fifth in an inner voice.
- Direct fifths or octaves by leap in both voices: No pair of voices reaches a perfect fifth or octave with both voices leaping in the same direction. It is allowed when the same chord only changes position and, in V → I, with the leading tone falling to the fifth in an inner voice. (Piston, ch. 3, pp. 30–31 and 34)