Unprepared seventh · Rules
The seventh of non-dominant chords (II7, IV7…) is prepared: the same note, in the same voice, in the previous chord. The seventh of V7 does not need it.
- Unprepared seventh: The seventh of non-dominant chords (II7, IV7…) is prepared: the same note, in the same voice, in the previous chord. The seventh of V7 does not need it. (Piston, ch. 23, p. 342)