Secondary Dominants

Theory 2.0 Guide: Secondary Dominants

Welcome to the music theory guide for Secondary Dominants! This guide is an analytical supplement to the YouTube video, which provides the visual score and audio examples. I also provide time stamps to the different concepts and examples that correspond with the video.

Part I: Dominant Function Time Stamp: 0:28

In functional harmony, chords in a key fit into one of three roles: Tonic, Pre-Dominant, Dominant [Table 1]. The Tonic chord is what all the other chords are working to get back to. A Pre-Dominant chord sets up a Dominant chord, and a Dominant chord wants to resolve back to the Tonic.

Table 1: Key of C Major Chord Roman Numeral Function C Major I Tonic D minor iio Pre-Dominant E minor iii Tonic* F Major IV Pre-Dominant G Major V Dominant A minor vi Tonic* B diminished viio Dominant *Note: While these chords are not the I chord, they share two of the three pitches in C Major which is why the can function as tonic. C Major has the notes C, E, G while A minor has A, C, E and E minor has E, G, B. In songwriting, this can be useful if you want to delay your final resolution till the end of the piece.

Dominant functioning chords have the move powerful resolution in functional harmony, specifically the Dominant 7th chord (V7). It has the most powerful resolution for two reasons:

1. The movement from the fifth scale degree in the bass back to the Tonic root, a perfect fifth interval.

2. The tritone resolution in the chord voicing. Tritones create effective resolutions due to their dissonance. This is what makes a Diminished 7th chord effective. Notice how a Dominant 7th chord has a Diminished triad in it, which is why both chords have the same function. The difference is the added fifth scale degree in the Dominant 7th chord.

Part II: Implementing Secondary Dominants Time Stamp: 1:20

Secondary Dominants function the same way as a normal Dominant chord, but they resolve to a chord that is not Tonic; they briefly tonicize another chord.

Here’s an example progression with no Secondary Dominants:

Ex. 1 I vi IV V7 I C Am F G7 C Time Stamp: 1:33

To implement a Secondary Dominant, pick a chord in the progression and find out what the Dominant of that chord would be. Using the chord A minor as an example, we need to find out what the Dominant of A minor would be.

Here are three tips on how to quickly find the Dominant of a chord:

1. Count five notes starting on the root of your chosen chord Ex: A, B, C, D, E

2. In a triad the third note is the Dominant in that key Ex: A minor has the notes A, C, E so E is the Dominant

3. A power chord is the root and fifth of a chord Ex: An A5 power chord is the notes A and E

After working through one of those steps, we find that E7 is the Dominant for A minor. The final step is putting E7 in front of A minor in our example progression.

When writing in roman numerals, a Secondary Dominant is written as “V/roman numeral of the chord it’s going to.” From our example, it would be V/vi. This is because the E7 is still a Dominant (V) functioning chord, but since it’s for A minor (vi); we must show that it is not in the original key of C Major.

Ex. 2 I V/vi vi IV V7 I C E7 Am F G7 C Time Stamp: 2:13

When using Secondary Dominants, you get accidentals from the implemented chords. E7 contains the note G#, which is not in the key of C Major. This chromaticism brings color, interest, and tension to the progression.

Part III: Implementation

There are no limits to how many Secondary Dominants you can use for a progression. Using our example progression, here is one for every chord:

Ex. 3 I V7/vi vi V7/IV IV V/V V7 I C E7 Am C7 F D7 G7 C Time Stamp: 2:45

Thank you for your support and stay tuned for more music theory videos and guides!