What Is a Secondary Dominant and How Is It Used in Tonal Music?

A secondary dominant is a harmonic device that expands the traditional dominant-tonic relationship to other diatonic chords, creating temporary tonicization and adding expressive color to a piece. In tonal music, the dominant chord (V) resolves to the tonic (I), establishing the key. However, composers often apply this same dominant relationship to non-tonic chords, producing a secondary dominant. These chords, also known as applied dominants, are essential for understanding harmonic tension and resolution in Western music.

Overview

In its most basic form, a secondary dominant is the dominant chord of a diatonic chord other than the tonic. For example, in C major, the dominant of the dominant (V/V) is D major, which resolves to G major (V). This creates a strong sense of movement toward the dominant chord, intensifying the eventual return to the tonic. Secondary dominants are notated in Roman numeral analysis as V/x, indicating that the chord is the dominant of chord x. They are typically major triads or dominant seventh chords, and they introduce chromatic tones that are not part of the home key’s scale.

How It’s Notated

Secondary dominants appear in various musical notation systems. In Roman numeral analysis, they are written with a slash and the target chord’s numeral. For instance, V/V means the dominant of the dominant, V/ii means the dominant of the supertonic, and V/vi is the dominant of the submediant. In lead sheet or chord symbols, they are often indicated as a simple letter chord with a slash and the target bass note, or with parentheses, like “D7” in C major (which is V7/V). Figured bass notation also shows them with accidentals and figures. The following table illustrates common secondary dominants in C major:

It is crucial to understand that the secondary dominant is not a modulation; the target chord remains within the original key, but the secondary dominant temporarily creates a new tonal center.

How It’s Performed

When performing secondary dominants, musicians must emphasize the chromatic alterations to bring out the temporary tension and release. The most distinctive note is often the leading tone of the temporary key, which must resolve upwards by a half step. For instance, in a V/V chord, the raised fourth scale degree (F# in C major) acts as a leading tone to G and should resolve to G. Performers should pay attention to voice leading to ensure smooth connections, often keeping common tones and moving the altered notes stepwise. In ensemble settings, intonation is critical because the raised notes must agree with the harmonic context.

How It Works

The theoretical mechanism behind a secondary dominant is tonicization—the process of momentarily treating a chord as if it were a temporary tonic. By constructing a dominant chord on the fifth scale degree of a non-tonic chord, the listener’s ear is briefly led to expect that chord as a resolution. This works because the dominant chord contains the leading tone of the target key, which creates a strong pull. For example, in C major, the chords are diatonic: I (C), ii (Dm), iii (Em), IV (F), V (G), vi (Am), vii° (Bdim). To create a secondary dominant for the ii chord, we use A major (V/ii), which resolves to D minor. The C# in A major is the leading tone of D, creating a temporary sense of D minor. The secondary dominant may appear as a triad or, more commonly, as a dominant seventh chord, adding further dissonance and urgency.

Origin / Etymology

The term “secondary dominant” is a translation of the German “Zwischendominante” (intermediary dominant) and was popularized in music theory textbooks in the 19th century. The concept, however, has been in practice since the Baroque era. The word “dominant” comes from Latin “dominari,” meaning “to rule,” reflecting the dominant chord’s controlling influence over the tonic. The prefix “secondary” distinguishes these applied dominants from the primary dominant (V) of the home key. Although the practice predates the terminology, the label became standard in theoretical treatises to describe these chromatic chords.

Historical Context

Secondary dominants have been used for centuries. In the Baroque era, composers like J.S. Bach used them to enrich harmonic progressions, as seen in his chorales and instrumental works. The Classical period, with composers such as Haydn and Mozart, integrated them into sonata forms and other structures, using them to create dramatic tension. The Romantic era expanded their use further, with composers like Chopin, Liszt, and Wagner exploiting their coloristic potential. In the 20th century, they became a staple in jazz and popular music, often called “applied dominants” or “secondary dominant chords.” Their versatility across styles makes them a fundamental harmonic tool.

Defining Characteristics

Secondary dominants are characterized by several features:

• They are major triads or dominant seventh chords.
• They contain at least one chromatic note not present in the home key’s scale.
• They resolve to a diatonic chord (the target) that is not the tonic.
• The resolution typically moves by a descending fifth (or ascending fourth) root motion.
• They often appear in strong metrical positions or on accented beats.
• They create a temporary sense of a new key without establishing a permanent modulation.

These characteristics make secondary dominants a powerful tool for harmonic color and expression.

Where You’ll Encounter It

Secondary dominants are ubiquitous in tonal music. In classical repertoire, they appear in virtually all genres: symphonies, sonatas, chamber music, and art songs. In jazz, they are fundamental to chord progressions, especially in genres like bebop and standards. In pop and rock music, secondary dominants often appear in chord progressions as a way to add sophistication without losing accessibility. Film scores use them to underscore emotional shifts. Whether in a Bach chorale or a Beatles song, secondary dominants are a key part of the harmonic language.

Key Figures

Many composers have showcased secondary dominants. J.S. Bach used them extensively in his chorales, demonstrating clear voice-leading principles. Wolfgang Amadeus Mozart employed them in his operas and symphonies to heighten drama. Ludwig van Beethoven’s piano sonatas and symphonies feature notable secondary dominants, often at pivotal moments. Frédéric Chopin’s nocturnes and preludes are replete with colorful applied chords. In jazz, pianists like Art Tatum and Bill Evans used secondary dominants to enrich their harmonic vocabulary. These figures exemplify the versatility and importance of this device.

Landmark Works

Specific pieces that highlight secondary dominants include J.S. Bach’s Chorale “Wachet auf,” where the harmony is rich with applied dominants. Beethoven’s Symphony No. 5, first movement, uses a famous V/V in the opening theme. Chopin’s Nocturne in E-flat Major, Op. 9, No. 2, contains numerous secondary dominants that create its distinctive expressive quality. In jazz, the standard “All the Things You Are” by Jerome Kern is celebrated for its chord progression laden with secondary dominants. These works serve as excellent examples for study.

Common Misconceptions

One common misconception is that secondary dominants are modulations. Unlike a modulation, a secondary dominant does not permanently change the tonal center; it only provides a temporary cadence to a non-tonic chord. Another confusion arises with borrowed chords (mode mixture), which involve chords from the parallel minor key, not creating a dominant function. Additionally, some may mistake any chromatic chord for a secondary dominant, but the chord must have a dominant function (i.e., a major triad or dominant seventh built on the fifth scale degree of the target chord). Understanding these distinctions is crucial for accurate analysis.

Secondary dominants remain an essential tool for composers and theorists alike. Their ability to infuse harmonic motion with color and tension enriches the expressive potential of tonal music. By mastering their use, musicians gain deeper insight into the grammar of harmony and the artistry of composition.