How to Improvise Over Secondary Dominants
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A secondary dominant is a chord that temporarily steps outside of the key, and into another related key. For example, in the key of C, we have Dmin7 as a II chord and a G7 as the five chord. But we can change the Dmin7 into D7, and then it functions as the V chord of G, briefly implying the key of G, but landing back in the key of C.
You probably won't be able to avoid secondary dominants forever. Most styles of music will make use of them at least occasionally. But this is an example of a musical event that many guitar players never learn to understand or deal with. We're going to give you the tools to improvise with secondary dominants here.
First, we're going to start with a diatonic chord progression that moves down in fifths. This is kind of brilliant, because now if we turn any of these chords into a Dominant 7th chord, it magically becomes a secondary dominant resolving to the following chord.
Let's try improvising a bit with no secondary dominants and that will be our first example through the chord progression.
Now, the second chord, Cmaj7 will turn into V of IV. This introduces a flat 7 into the key, which is B flat.
Now the chord in the fourth measure turns into B7 which is V of III, and which introduces both #2 and #4 into the key. So we'll play D# and F# instead of D and F.
Now, in measure five we'll have E7, which is V of VI, introducing #5 into the key. So we'll play G# instead of G.
In Measure six, we'll have A7, which is V of II, introducing #1 into the key. So we'll play C# instead of C.
And in Measure seven, we'll have D7 which is V of V, introducing the #4 into the key. So we'll play F# instead of F.
Alright, try these out for yourself! Try to remember how each secondary dominant functions. Is it V of II? V of V? And try to memorize which altered notes are brought into the key by each of these secondary dominants.
Introduction
In this lesson, we’ll learn how to deal with secondary dominantA chord, sometimes major but usually dominant 7th, which is borrowed from a closely related key, and which resolves to a chord within the key by way of the V/I relationship.s in an improvisation setting.
We’ll do this by practicing over a series of backing tracks, each based on the same chord progression, but each with a different secondary dominant added.
Secondary dominants are quite common even in popular music, and understanding how to deal with them will give you an increased sense of confidence to handle all of the situations you may encounter as a guitar player.
The “plain vanilla” chord progression
This chord progression cycles through all of the chords in the key of C major using a root motion of perfect fourths.
Because the motion is in fourths, any chord will automatically be a secondary dominant if turned into a dominant 7th chord. For instance, if the Cmaj7 is turned into a dominant 7th it becomes V/IV, and resolves properly to IVmaj7, as in our next example.
| Cmaj7 | Cmaj7 | Fmaj7 | B-7♭5 |
| E-7 | A-7 | D-7 | G7 |
Backing Track 1
V/IV instead of Cmaj7
This introduces the note ♭7 into the key (in this case, B♭). So instead of playing the C major scale, you could switch to the C Mixolydian scale for the dominant chord. Or you could just concentrate on changing B into B♭, which may more productive.
| Cmaj7 | C7 | Fmaj7 | B-7♭5 |
| E-7 | A-7 | D-7 | G7 |
Backing Track 2
V/III instead of B-7♭5
This introduces a D♯ into the key. You could think of that enharmonically as C melodic minor, or just focus on turning the D into D♯. But it’s also a good idea to avoid playing an E over the B7 chord.
| Cmaj7 | Cmaj7 | Fmaj7 | B7 |
| E-7 | A-7 | D-7 | G7 |
Backing Track 3
V/VI instead of E-7
This introduces G♯ to the key, which would turn C major into C Ionian ♯5. Ionian ♯5 is also the third mode of the Harmonic minor. So V/VI introduces the harmonic minor scale built on the sixth degree, in this case A harmonic minor. You can imagine that the key is A minor and the V7 has arrived so the scale switches to harmonic minor.
| Cmaj7 | Cmaj7 | Fmaj7 | B-7♭5 |
| E7 | A-7 | D-7 | G7 |
Backing Track 4
V/II instead of A-7
This introduces a C♯ into the key. Because that's the root of the key, you can imagine that the new scale is like a C♯ scale where every note is flat. This is called the super locrian or altered scale, and it is a mode of the melodic minor scale. You can amuse your friends with this story, or just switch the C’s in your improvisation to C♯.
| Cmaj7 | Cmaj7 | Fmaj7 | B-7♭5 |
| E-7 | A7 | D-7 | G7 |
Backing Track 5
V/V instead of D-7
This introduces a ♯4 to the key, which means you can play C Lydian, or just focus on changing any F notes to F♯.
| Cmaj7 | Cmaj7 | Fmaj7 | B-7♭5 |
| E-7 | A-7 | D7 | G7 |
Backing Track 6
Coda
Practice all of these tracks, and also consider improvising in multiple positions. This way, you’ll know exactly how to handle secondary dominants when they come your way. Which may be surprisingly often.
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.