Secondary Dominants Explained: V of V and Beyond

A secondary dominant is a dominant 7th chord that resolves to a chord other than the tonic. It's borrowed from outside the key to set up a temporary "false tonic." Secondary dominants are how Tin Pan Alley, jazz, and sophisticated pop achieve harmonic complexity without leaving the original key for long.

The V Chord (Refresher)

In any major key, the V chord is the dominant. In G major, the V is D (or D7). The V wants to resolve to the I (G). This is the strongest harmonic move in tonal music.

What "V of V" Means

"V of V" (written V/V) is the dominant of the dominant. It's the chord that would be the V if your destination chord were the tonic.

In G major, the V is D. The V of D would be A (since A is the V of D). So V/V in G major is A (or A7).

When A7 resolves to D, the D feels temporarily like a tonic. Then D resolves back to G (the real tonic). The journey: A7 → D → G. Each step a strong dominant resolution.

Common Secondary Dominants

• V/V: dominant of the dominant. In C major, that's D7 → G → C.
• V/vi: dominant of the relative minor. In C major, that's E7 → Am.
• V/IV: dominant of the IV. In C major, that's C7 → F.
• V/ii: dominant of the ii. In C major, that's A7 → Dm.
• V/iii: dominant of the iii. In C major, that's B7 → Em.

Each adds one chromatic note to the key but resolves naturally. The chromatic note is what gives the secondary dominant its color.

Songs That Use Secondary Dominants

• "Yesterday" by The Beatles uses E7 → Am (V/vi → vi) in the verse.
• "Take On Me" by a-ha uses multiple secondary dominants.
• Most jazz standards. Secondary dominants are the foundation of bebop progressions.
• Most Tin Pan Alley. The Great American Songbook uses secondary dominants throughout.

How to Hear Secondary Dominants

Listen for chord changes that feel like resolutions but don't go to the tonic. If a chord feels like it's pulling toward another chord (and that chord isn't the I), the leaning chord is probably a secondary dominant.

Practice: pick a song with a secondary dominant (like "Yesterday"). Sing the bass line. Notice where the bass moves by a fifth or fourth. Those movements often signal a secondary dominant resolution.

Sources

Secondary dominants are a core jazz and classical theory concept. References: MusicTheory.net covers secondary dominants. Open Music Theory has detailed analysis with examples. Berklee Online's harmony sequence treats secondary dominants as a primary tool for chord-progression construction.

FAQ: Secondary Dominants Questions

Why is it called a "secondary" dominant?

Because it's the dominant of a chord other than the tonic. The "primary" dominant is the V of the actual tonic. A "secondary" dominant is the V of any other chord.

How do I find the V of a chord?

Count up a perfect fifth. The V of D is A. The V of Am is E (or E7). The V of F is C.

Are secondary dominants the same as borrowed chords?

Related but different. Borrowed chords come from a parallel key (like the bVII borrowed from minor). Secondary dominants are dominant 7th chords aimed at a non-tonic destination. Both add chromatic color, but the mechanisms differ.

Do secondary dominants leave the key?

Briefly. The secondary dominant introduces a chromatic note that's not in the original key. The chord it resolves to is back in the key. The "trip outside the key" is short.

How do I use secondary dominants in my own songs?

Pick a chord progression. Identify any chord that's two beats or longer. Insert a V7 of that chord one bar before. The V7 will set up the chord and add harmonic interest.