AP® Music Theory · Unit 5 · Topic 5.3
IV7, vi7, and Other Predominant Sevenths
Adding a seventh to IV or vi turns it into a four-note predominant chord, but no matter the chord's quality, that seventh always falls by step into the next chord.
Predominant chords sit between tonic and dominant, pushing the harmony toward V. Stack a third on top of IV or vi and you get IV7 or vi7, four-note chords that still do the predominant job but with an extra voice to manage. That extra note is the chordal seventh, and it is a dissonance against the root. Dissonances in common-practice harmony do not just sit there; they move toward consonance, and the rule for every chordal seventh, regardless of which chord it belongs to or what quality that chord has, is the same: it resolves down by step into the next chord. IV7 is a major-minor mix of thirds built on IV, vi7 is built on vi, and both differ in sound and construction, but both obey this one resolution habit because the seventh's behavior comes from its dissonant interval against the root, not from the chord's role or color.
Mechanically, the seventh is usually prepared, meaning it appears as a note already present in the previous chord, held over so it does not leap in from nowhere. It then resolves downward by step, often while the other voices move normally into the next chord, landing on a note that is consonant against whatever root follows. This downward-by-step motion is non-negotiable: it does not matter if the chord is tonic-family like vi, predominant like IV, or dominant like V7, the seventh always falls.
This matters for the progression because predominant sevenths typically lead into V or V7, and the seventh's downward resolution often lines up with smooth, stepwise voice leading into the dominant's own chordal seventh or into its root. Connecting to inversions and six-four chords nearby in this unit, a predominant seventh in first inversion keeps the same resolution rule for its seventh; only the bass note and spacing change.
Key terms
- Chordal seventh
- The note a seventh above the root of a chord, treated as a dissonance that resolves down by step.
- Predominant function
- The harmonic role of chords like IV, ii, and vi that lead from tonic toward the dominant.
- Preparation
- Having a dissonant note, like a chordal seventh, already present as a held tone in the previous chord.
- Resolution
- The stepwise motion of a dissonant note into a nearby consonant tone in the following chord.
Watch it explained
- How it worksHow does every chordal seventh in common practice get prepared and then resolved down by step?
- Worked exampleFind the notes and quality of IV7 in B flat major and trace its seventh resolving.
- Common mistakeWhy doesn't the seventh in a vi7 chord resolve upward into the root of the next chord?
- Going furtherWhat changes when a predominant seventh appears in first inversion instead of root position?
Check yourself
End of topic.