Secondary Dominant Chords

A dominant chord creates a gravitational “pull” towards its tonic chord. There are several factors that create this relationship. While we can analyze this effect and come up with a reason for it, the real reason it works this way is that we expect that it will. This expectation comes from many hours listening to music over a lifetime.

Let’s consider the cadenceA resolution, or feeling of finality, created by moving from a strongly tense and unstable chord, to a stable one. Usually supported by the notes in the melody as well. The most common cadence is V–I. between V⁷ and I, in the key of C major.

Note: all of the chords above are from the notes of the C major scale. This is important.

When the G⁷ chord arrives, we can hear a tension that will be resolved when the C chord arrives. Why does one chord make us “expect” to hear another one next?

Resolution of Dominant Chords

The G⁷ chord (left) has the notes G, B, D, F. The C^maj chord (right) has the notes C, E, G.

As you read each of these points, make sure to look for them in the example before you move on to the next.

How the chord resolves

This type of chord movement between V and I is the basis of modern music. Popular songs consist mostly of V and I chords, with IV being popular as well. In more complex music, we can consider this cadenceA resolution, or feeling of finality, created by moving from a strongly tense and unstable chord, to a stable one. Usually supported by the notes in the melody as well. The most common cadence is V–I. to be a sort of punctuation, like a period—or even an exclamation mark. It signals a halt to motion, a point of rest.

Borrowing More Dominant Chords

A cadence creates a strong sense of tonalityThe key in which a piece is played, and the relationships of the notes to each other, and most especially to the tonal center.. The G⁷ chord is not like the C chord, but they complete each other. When the G⁷ chord appears, it sounds natural that a C chord will follow. The relationship between V⁷ and I is so powerful that we can actually borrow a V⁷ chord to use even when it doesn’t belong in the key, and it has the same function. Let’s consider the example again:

If we want to strengthen the A^min chord, we can put an E⁷ chord in front of it. The E⁷ does not belong in the key of C, but we can borrow it any way because of the strong relationship it has with the A^min chord. This creates an effect called tonicizationA method of composition which, usually temporarily, gives rise to the feeling that the tonal center has changed. For instance, the VI^min can be tonicized by preceding it with the V/VI secondary dominant chord..

Notice that the “E7” chord does not belong in the key of C. It contains the tone G♯ which is not in the key. But this is why it works: it is new and unexpected, and it resolves strongly to the A^min chord, which does belong.

This is useful for two reasons:

Secondary dominant chords are popular in all forms of music. There’s a secondary dominant in the national anthem of the United States. Listen to the song during the lyrics, “that our flag was still there” and you will hear an unusual note on the word “still”. This note is the third of a secondary dominant chord resolving to the V chord of the key. In the melody, you hear it resolve up to the fifth of the key. Secondary dominants have become less used in American pop music, but overall they are quite common.

Put It Into Practice:

With a pen and a piece of paper, fill out the following chart for Secondary Dominants in the key of C major.

Key Questions

As the creator of Hub Guitar, Grey has compiled hundreds of guitar lessons, written several books, and filmed hundreds of video lessons. He teaches private lessons in his Boston studio, as well as via video chat through TakeLessons.