Secondary dominants take the form V/x or V7/x, where x is a normal scale degree. They are the dominant chords of scale degrees other than the tonic, and they’ll typically include at least one note from outside the key. They usually then resolve to x, although sometimes they’ll resolve to a different chord, creating a deceptive resolution.
Most of the concepts we’ve discussed so far allow us to pick a key, remember the notes of that key and stay there. Now we’ll begin to discuss chromaticism, in which we are writing in a particular key and we use notes from outside that key.
Why, you might ask, would we want to stray from the key? Many, or even most, great pop songs only contain notes from their original keys.
The answer is that by using notes from outside the key, we can point the listener’s ear in directions we wouldn’t have been able to if we only used notes from within it. If we use them correctly, these chromatic notes can be quite striking, and perhaps even song-defining.
One possibility when we’re using notes from outside our major or minor scales is to just ditch tonality altogether and head boldly into atonality. This is an approach often favored by metal bands and avant-garde rock acts. The wildness of some of these bands can be thrilling, but that’s not the approach we’ll take here. Instead, we’ll mostly use chromatic notes to emphasize existing notes from within the key.
Remember all the way back in Chapter 7 when we discussed leading tones? Understanding leading tones can help us understand chromaticism as well.
The leading tone is a half step below the tonic, so if we’re in D major, our leading tone is C#. Whether we’re in major or minor, the leading tone will often appear within a V chord, and when we hear it, our ears want the leading tone to resolve to the tonic. That is, when we’re in the key of D major, we want to hear C# resolve to D. The same goes for the key of D minor, where C# frequently appears despite not being written in the key signature itself. Here, for example, we have an A major chord (V) resolving to a D major chord (I).
If we were to hear these chords in the context of a passage that’s clearly in the key of D, our ears would pick up on that C#, and we would want that note to resolve to the tonic. More generally, we would also want to hear the V chord resolve to I.
Here’s where chromaticism comes in: What if we could have leading tones for notes other than the tonic?
In classical music, the leading tone is crucial to our perception of what key we’re in. That leading tone will frequently occur within the V chord. So we can use the leading tone and V chord of another key to temporarily “point” at that key.
For example, V in the key of D major, as we’ve seen, is A. The leading tone of A is G#. G# isn’t in the key of D major (D E F# G A B C# D), but we can still use G# in the key of D major to “point” at A. The way we’ll usually do that is to use it in the context of an E major chord, which is the V chord in the key of A.
When the E major chord appears in the key of D major, we usually call it V/V, pronounced “five of five.” It’s the V chord of the key of V (A major).
We can create secondary dominants for a wide variety of chords, major or minor. Here are a few common ones, all in the key of D major.
Usually, the “numerator” (my non-technical name for the Roman numeral to the left of the slash) is either V or V7. The “denominator” tells us which key the numerator comes from, and which chord it will resolve to – V/ii will go to ii, V7/vi will go to vi, and so on.
Here’s an example. Charlie Puth’s “One Call Away” mostly uses standard chords from its home key of Db major, but features a very prominent secondary dominant at a key moment near the end.
The F7 chord contains an A, which is not in the Db major scale (Db, Eb, F, Gb, Ab, Bb, C, Db). The F7 is not a chord from the key of Db major, but a secondary dominant — a V7/vi, to be exact, since it sets up the arrival of the vi chord, Bbm. The A in the F7 chord is a leading tone to Bb, and it points our ears in the direction of that chord. Puth does not use the F7 chord in the other choruses of the song, and his use of a single V7/vi has a great dramatic impact, setting up the reentry of the drums at 3:07.
The chorus of the Bangles’ “Eternal Flame” is in the key of G, and it contains two secondary dominants.
The chorus begins with a typical I-vi-IV-V progression, but with a vi7 in place of vi. In the third line, though, the Bangles use a B7 chord, which contains a D#. That D# acts as a leading tone that points at E, and so it’s no surprise that the Bangles then return to Em7. The B7 chord occurs at the melodic peak of the chorus, and the Bangles are using a secondary dominant – a V7 from the key of E minor – to heighten the tension right at this key point in the music.
Two chords later, there’s an A7, which contains a C#. Like the D#, this C# is not in the key of G. Instead, it acts as a leading tone that points at D, and the progression goes straight from A7 to D, as expected. The A7, then, is called a V7/V – it’s a V7 chord from the key of D, and D is V in the key of G.
The verse of Billy Joel’s “The Longest Time,” which is in the key of Eb major, features three secondary dominants. (The precise chords of this a cappella song are difficult to track, but what follows is close enough.)
The first of these three secondary dominants occurs in the second line above, which features an F7 chord (F, A, C, Eb). The A in this F7 is not in the key of Eb major. Here, it acts as a leading tone to the key of Bb major, and sure enough, a Bb major chord appears next. Or, to put it differently, F is the dominant chord in the key of Bb major, and its appearance helps point our ears, briefly, toward Bb major. Listen carefully to the differences between the lines “if you said goodbye to me tonight” and “there would still be music left to write” – the chords underpinning them sound somewhat similar, but note the way the F7 gently nudges our ears toward the Bb.
The chord after that, G, again features a note (B) that isn’t in the key of Eb major. This B serves as the leading tone to C, and the next chord is C minor.
The last secondary dominant is subtler. The line “I’m so inspired by you” is accompanied by ordinary V and I chords, but listen for the way Joel’s vocal melody reaches down for a Db – another note that isn’t in the key of Eb – on “you.” This Db isn’t the leading tone of a new key. Instead, it’s the seventh of an Eb7 chord that points our ears toward Ab. This Eb7 chord is called V7/IV (that is, the V7 of the key of IV, which is Ab).
V7/IV is a particularly interesting secondary dominant. To understand why, think about V/IV might be in the key of G. IV is C, so we think about V in the key of C, which is … G! So V/IV in the key of C is G.
The problem with that is that if we’re in the key of G and we play a G major chord, our ears will simply tell us, “I recognize that! That’s the I chord.” Without more context, our ears won’t recognize the G as a V/IV. Secondary dominants generally contain notes from outside the key, and that’s how we know we’re hearing something unusual.
So instead of plain old V/IV, we’ll frequently hear V7/IV. In the key of G, V7/IV would be G7, which contains an F natural. F natural is not in the key of G, so that note cues our ears that something strange is going on.
Try playing the following progression in the key of G major:
Notice how the G7 chord sounds. The F natural is unexpected, and it points our ears down to the E in the C chord.
Bob Dylan (not an artist generally known for adventurous chord changes) uses a couple secondary dominants, including V7/IV, in “Don’t Think Twice, It’s Alright,” which is in the key of E major.
The first secondary dominant to appear is the F#7, which contains an A#, a note outside the key of E that serves as the leading tone to B. Then, in the following line, Dylan includes a V7/IV chord, which in this case is E7. That chord contains a D natural, which is outside the key of E and which warns our ears we’re about to head elsewhere — namely, to A, as the D points down at the C# within the A chord.
|Quick Quiz 14.1
Name the notes of the following chords. Remember that each of them should contain notes from outside their key!
V/vi in Bb major
Why Secondary Dominants Appear More Frequently In Major Keys
You might have noticed that all the examples we’ve discussed so far have been in major keys. We can also use secondary dominants in minor keys, with V/iv, V/V and V7/VI being among the more common possibilities. However, pop songwriters generally use secondary dominants much less frequently in minor keys than in major. Secondary dominants in minor are often far removed from the tonic (for example, V/V in A minor is B major), so they can sound harsh. In Chapter 7, we discussed how contemporary pop songs in minor often sound ambiguously close to major. The presence of potentially harsh secondary dominants sometimes threatens to disrupt that ambiguity.
In some cases, a secondary dominant will create an expectation that the music is heading in a particular direction, only to confound us (well, slightly) by going somewhere else. Depending on the context, this is often called a deceptive resolution. Here’s one common possibility from the Wallflowers’ “One Headlight” (a song written by Jakob Dylan, who might have inherited his ear for secondary dominants from his dad). It occurs right before the chorus, which is in D major.
By placing the F# major chord right before the chorus, the Wallflowers create (if only briefly) the expectation that we will hear a B minor chord. They then lightly subvert those expectations by heading to the IV chord, G, instead. This makes sense for two reasons. First, a common device in classical music and in other genres is to go from V to i, and a common way of subverting that expectation is by going from V to VI. In classical music, when we do this at the end of a phrase, we call it a deceptive cadence. “One Headlight” does something similar, but with a secondary dominant – the F# chord points to B minor, and G is VI in the key of B minor.
Also, the expected resolution of the F# chord (B minor) contains two notes in common with the actual resolution of G major (B and D). Notice, too, that the F# chord arrives at an important point in the song—right before the chorus. The chord creates the expectation that something important is about to happen.
V/vi (or V7/vi) to IV is a fairly common progression – the two chords often sound terrific together. Another characteristic example occurs in the chorus of the Foundations’ “Build Me Up.”
It’s probably a coincidence, but it’s amusing that the Foundations are singing about being built up and let down, since that’s exactly what the progression does. Typically, we expect V7/vi to resolve to vi, which in this case would be A minor.
Secondary Leading-Tone Chords
Secondary leading-tone chords, in which we use viio/x, viio7/x or viiø7/x in place of V/x or V7/x, can provide an uncertain-sounding variation on the secondary dominant.
Secondary dominants and secondary leading-tone chords are similar in function — they use the leading tones of different keys to point at various scale degrees. For example, if we’re in the key of A major, the V/ii chord (F# major) uses the leading tone of ii, A#, to point up at B. The viio7/ii does exactly the same thing — it’s an A#o7 chord that also points to B.
A good example occurs at the beginning of Garth Brooks’ “Friends in Low Places.”
Brooks’ progression of I to viio7/ii to ii creates clever chromatic motion from A to A# to B. We could substitute V7/ii for viio7/ii and it would sound fine. But the diminished quality viio7/ii helps create a sense of unease in the verses that contrasts with the song’s celebratory choruses.
|Quick Quiz 14.2
Consider the beginning of ABBA’s Dancing Queen, which is in the key of A major.
What is the C#7? Does it resolve normally?
Write a verse that includes a secondary dominant. Make sure the secondary dominant resolves in the normal way.
Next Chapter: Borrowed Chords
Quick Quiz Answers
V/vi in Bb major = D major (D, F#, A)
V7/IV in A major = A7 (A, C#, E, G)
V/V in F minor = G major (G, B, D)
The C#7 is a V7/vi, and yes, it resolves normally. The C#7 contains an E#, which is not in the key of A. Instead, that E# becomes the leading tone to F#, and pushes our ears in the direction of the F#m chord that follows. (The astute reader will note that the B/D# chord is also not in the key of A. That chord functions somewhat differently than the C#7, so we will ignore it for now.)