Coming up with new songwriting ideas is a regular challenge for any artist.

When the well runs dry you need to use every trick in the book to reignite that spark of creativity.

Luckily, music theory is one of the best places to turn to grow your pool of ideas.

Today I’ll explain a music theory concept that can help your chord progressions break away from the expected and even venture outside the key.

It’s called secondary dominants.

What are secondary dominants?

Secondary dominants are chords from outside the home key that are related to chords in a progression by a V-I relationship.

That may sound technical, but it’s not that complicated.

If you want to go back over the basics, check out how chords are built on the degrees of the scale, and maybe get a little refresher on key signatures or the circle of fifths if you need it.

Why use secondary dominants?

Writing songs where every single chord comes from the home key can get stale pretty fast.

There’s obviously no limit to what you can do with the basic diatonic chords. But switching up your listeners expectations’ with other chords is a powerful technique.

Secondary dominants are a great choice to bring related but unfamiliar chords into your progressions.

Secondary dominants are a great choice to bring related but unfamiliar chords into your progressions.

Secondary dominants explained

If you’re feeling comfortable with your key signatures and closely related keys, I’ll give you an example to help explain the concept of secondary dominants.

Imagine a basic I-IV-V-I chord progression. It’s easy to feel the tension build and release as the tonic chord moves to a predominant, dominant and then back again.

As in most chord progressions, The V chord is the high point of the drama and tension here.

To build the intensity as you go toward V you need to use another dominant chord. In this case it’s easy.

Right before the IV in the current progression, I’ll add the dominant seventh chord of the IV chord itself to the progression.

Here’s how it sounds and how it’s written with Roman numerals.

V7/IV pulls the tonic chord more forcefully toward IV and emphasizes the predominant harmony before V7.

Writing songs where every single chord comes from the home key can get stale pretty fast.

V7/IV may look slightly alarming on the page, but it makes much more sense when you evaluate the note names themselves.

IV in the key of C major is F. To find V7/IV, count up to the fifth degree as if you were in the key of F major.

Spelling out a V7 chord on this scale degree gives you C7: C-E-G-Bb

That’s it! V7/IV in C major is C7. Now take a look back at your four note diatonic chords.

The four note chord built on the first degree of the C major scale is CMaj7. Its formula is: C-E-G-B

Notice that it’s just one accidental away from V7/IV.

That’s what it means for keys to be closely related. C major and F major are one step away from each other on the circle of fifths.

That means they share all their notes except one—Bb.

It also means that borrowing chords from this key won’t sound too out of place. They’re closely related!

That’s what it means for keys to be closely related. C major and F major are one step away from each other on the circle of fifths.

Where to use secondary dominants in your songs

Secondary dominants are especially easy to use if you have a solid knowledge of key signatures and chord spellings.

The most common ones in pop music function as predominant chords before IV and V, although they can be used before other chords too.

Here’s a notable example to help you get the sound in your ear.

In the intro to “Bohemian Rhapsody,” the multi-tracked choir sings two rich secondary dominants.

V7/V appears in measure two to emphasize the progression’s third chord—V7. And V7/IV helps the song feel stable enough to rest on predominant harmony in measure seven.

Here’s the progression:

Cool songwriting techniques

Secondary dominants are one of the many inspiring songwriting tools you can learn from music theory.

It may take a bit of practice with key signatures and chord building to get comfortable with them, but once you do you’ll have access to a powerful sound in your chord progressions.

Now that you have a start with secondary dominants get back to your session and keep your songwriting flowing.