If you’ve ever wondered how composers and songwriters add unexpected color and movement to their music, the answer often lies in secondary dominant chords and the second leading tone. These harmonic tools can create tension, anticipation, and a sense of forward motion, making music feel more dynamic and expressive.
In this post, we’ll explore what secondary dominants are, how they introduce a second leading tone, and how you can use them in your own playing and compositions.
What Are Secondary Dominant Chords?
In traditional harmony, the dominant (V) chord plays a crucial role in establishing and reinforcing the tonic (I). It creates tension that naturally resolves back home. But what if you could create temporary tension leading to a chord other than the tonic? That’s where secondary dominants come in.
A secondary dominant is a dominant (V) chord that temporarily tonicizes a chord other than the I. It borrows the tension-building power of a dominant chord to momentarily highlight another degree in the scale. These chords are often labeled as V of (or V7 of) the chord they target.
Common Secondary Dominant Chords
Let’s take the key of C major as an example:
• The V chord (dominant) is G7, which resolves to C.
• If we temporarily treat Dm (the ii chord) as a tonic, we can precede it with its own dominant: A7 (V7 of ii).
• Likewise, we can introduce other secondary dominants:
• D7 (V7 of V, leading to G)
• E7 (V7 of vi, leading to Am)
• B7 (V7 of iii, leading to Em)
Each of these secondary dominants introduces notes that are not in the original key, adding chromaticism and richness to the harmony.
The Role of the Second Leading Tone
In diatonic harmony, the leading tone is the 7th scale degree, which resolves up to the tonic. However, when we use secondary dominants, we introduce a new leading tone that resolves to a note other than the tonic.
For example, in C major:
• The natural leading tone (B) resolves to C.
• But in the A7 chord (V7 of ii), we introduce C#, which acts as a new leading tone resolving to D.
This “second leading tone” creates additional harmonic motion and a sense of urgency, enriching the musical texture.
How to Use Secondary Dominants and the Second Leading Tone in Your Playing
1. Enhance Progressions – Instead of a standard ii–V–I, try V7 of ii → ii → V7 → I for more movement.
2. Spice Up Melodies – If a melody lingers on a note, see if you can harmonize it with a secondary dominant to add color.
3. Modulation Gateway – Secondary dominants often hint at key changes. A V7 of vi, for instance, can lead smoothly into the relative minor.
Final Thoughts
Secondary dominants and the second leading tone are powerful tools that add excitement and tension to your music. Whether you’re improvising, composing, or analyzing your favorite pieces, recognizing these elements will deepen your understanding of harmony and open up new creative possibilities.
Try incorporating secondary dominants in your playing and listen to how they transform the musical journey!
