The first secondary chord you learned about, V/V, introduced a scale degree outside the major scale (♯4). This doesn’t always have to be the case, however. Just as we did in the previous section with V/V, let’s figure out which scale degrees are in a V/IV chord. Again, we start with the C major scale on the piano:
C major scale
Then we look at the major scale that starts on scale degree 4 of the C major scale since we want to temporarily establish the IV as a new home base. This is the F major scale.
F major scale
Next we build a V chord (scale degrees 5, 7, and 2) in this new scale.
V chord (scale degrees 5, 7, and 2) in F major
Finally, we look at these same notes but back in the C major scale.
V/IV chord in C major
We see they correspond to scale degrees 1, 3, and 5: the I chord! Evidently, the V/IV and the I are the same chord. Typically there is no need to differentiate between a V/IV chord and a I chord that may or may not be functioning as a V/IV. If you play a chord with scale degrees 1, 3 and 5, you’re playing a plain old I. There is, however, one important instance when it does become necessary to make the distinction, and that is when V/IV is written as a seventh chord, i.e., V⁷/IV.
Let’s explore this in the following exercise:
Check for Understanding
Unlike V/IV, V⁷/IV contains a scale degree outside the major scale. Below, we will guide you through the process of figuring out what scale degree it is. Just as we did previously, we start with the C major scale on piano:
C major scale
Then we build a major scale that starts on scale degree 4 of the C major scale since we want to temporarily establish the IV as a new home base. This is the F major scale.
F major scale
Next we build a V⁷ chord (scale degrees 5, 7, 2, and 4) in this new scale.
V⁷ chord in F major
Now all that is left to do is figure out the degrees of the C major scale the highlighted notes correspond to.
The exercise above shows that V⁷/IV contains scale degrees 1, 3, 5, and ♭7, and has a dominant seventh quality. Contrast this with I⁷, which contains scale degrees 1, 3, 5, and 7, and has a major seventh quality. This means that while V/IV and I are the same chord, V⁷/IV and I⁷ are not.
To hear this difference, compare the progressions of “Desperado” by The Eagles and “Fallin’ for You” by Colbie Caillat. Both songs connect the I chord and the IV chord with a seventh chord built on scale degree 1. “Fallin’ For You” by Colbie Caillat uses a I⁷ (a C major seventh, Cmaj7).
“Fallin’ for You” by Colbie Caillat
On the other hand, “Desperado” uses a V⁷/IV (a C dominant seventh, C7).
“Desperado” by the Eagles
Both of these progressions are common, and though the difference is subtle, it’s worth understanding functionally why both versions work. As a secondary chord, the V⁷/IV in “Desperado” will almost always go to IV. The I⁷ in “Fallin’ for You”, on the other hand, is not playing a specific role, and can go to a number of different chords. It need not go to the IV as it does here.
“Something” by The Beatles is an example of a song that uses both the I⁷ and the V⁷/IV. The song starts on I and transitions to I⁷ before going to V⁷/IV → IV.
“Something” by The Beatles
V/vi
The secondary chords we’ve discussed so far have all been V chords of a major chord (V/IV and V/V), but minor chords can be made the targets of secondary V chords as well. The most common example is V/vi.
Instead of telling you how the V/vi chord is built, let’s see if you can figure it out based on what you’ve learned so far:
Review
Part 1 of 3. In the key of C major, what note is the bass of the vi chord? (use the basic chords in each key, below, if needed)
E
B
A
G
Part 2 of 3. What is the V chord in the key of A major?
E major
F major
D major
C major
Part 3 of 3. The E major chord is built off the third scale degree of the C major scale. What chord is normally built off the third scale degree of the C major scale?
E major
E minor
E dim
F major
The V/vi chord contains scale degrees 3, ♯5, and 7. Note that even though the target of V/vi is a minor chord (vi), V/vi itself is still a major chord. Like other secondary chords, it has a strong pull to its target chord. Let’s listen to some examples:
“Hallelujah” by Leonard Cohen does a standard I → IV → V progression before using V/vi to get to vi:
“Hallelujah” by Leonard Cohen
Adele’s “Rolling in the Deep” uses the V/vi to break the pattern established by the first half of the prechorus to create a strong, unexpected cadence to the vi in the chorus. Here, the song cleverly exploits the similarity between iii and V/vi (which share scale degree 3 in their bass) to set up this cadence.
“Rolling in the Deep” by Adele
As with previous secondary chords, V/vi can also show up as a seventh chord (V⁷/vi), as in “She’s Always a Woman” by Billy Joel.
“She’s Always a Woman” by Billy Joel
V/vi is a very common secondary chord. One of the reasons this chord is so important and common is the relationship that the vi chord has with songs written in a minor key. We’ll be learning all about minor progressions in Chapter 5.
Check for Understanding
Secondary chords sometimes introduce scale degrees that are outside of the scale. Because of this, secondary chords often create a tension that begs for a resolution to a chord that is in the scale. What scale degrees do the V⁷/IV and V/vi chords introduce that are outside of the scale?
Check for Understanding
Explain the importance of using the secondary chord V/IV in its seventh chord version, V⁷/IV, and why this is different from V/V or V/vi.
Check for Understanding
Part 1 of 3: How do V⁷/IV and V/vi typically resolve? That is, what chords usually come after these chords to relieve the tension created by the scale degrees that are outside of the scale?
Part 2 of 3: In classical music theory, a general rule of thumb is that sharped scale degrees have a natural tendency to resolve upward to the nearest scale degree (e.g., ♯4 → 5), whereas flatted scale degrees like to resolve downward to the nearest scale degree (e.g., ♭3 → 2). Explain how the chord resolutions in the answer to Part 1 are consistent with this rule. Hint: Write out the scale degrees of each secondary chord and the chord it resolves to.
Part 3 of 3: Although the tendency for secondary chords like V/vi to go to their targets (vi in this case) is mostly due to the strong relationship between V and I chords, the rule from Part 2 reinforces this tendency. This rule would also suggest that other chords containing scale degree 6 might be good targets for V/vi. What other basic chords besides vi contain scale degree 6?
