BAD ROMANCE: Secondary Dominants

For this article, you need to know:
- The Basics (notation, notes, scales, keys, intervals, triads)
- Cadences

So you know about dominant chords and how they lead to tonic chords, right? V goes to I. (or, in a minor key, V goes to i). An authentic cadence. And doesn't it seem like both chords are emphasized whenever this happens? It sort of forces the listener to focus on that movement between the chords, to feel it in their chest. (...Sometimes.)

We can get this emphasis to fall on chords other than I. In fact, we can get it on any chord, using what we call secondary dominants. To explain them, let's look at a short chord progression:

I  IV  V/V  V

You'll notice there's a new chord here: the V/V. This is a secondary dominant, and it is pronounced "five of five". How do you play it? Just start on the V of your key, count up five more, and play the major triad based off of that note. So if we're in C major, we can write in the chord names for this progression:

C:	I	IV	V/V	V
	C	F	D	G

To get to that D major triad, we started on G (the V of C major), and took the note a perfect fifth above that, then built a major triad on it. It's as if we pretended for a moment that our key was G major, and just played the V chord. In fact, that's exactly what we did!

Notice that all four of these chords are major, since they have capital letters. But D isn't usually a major chord, if we're in the key of C major. The ii chord is minor in any major key! And, if we've got a D major chord, one of its notes will have to be an F♯, and there's no F♯ in the C scale! What's going on?

See, a secondary dominant is actually a momentary modulation, or transition from one key to another. When we wrote V/V, we actually moved into the key a fifth up from the tonic (the dominant key) - in this case, G major. And we played that key's V chord, which is D. Since G major does have an F♯, it makes sense that we're playing D (D-F♯-A) and not d (D-F♮-A).

That F♯ is important for another reason, too: it functions as the leading tone of the temporary key (G major). It makes the listener want to hear a G, creating that tension we were talking about before.

Gaga uses a secondary dominant in the chorus of "Bad Romance", which is in A major. The progression is:

("I want your love and I want your revenge; you and me could write a bad romance; whoa--/
I want your love and all your lover's revenge; you and me could write a bad romance")

A:	IV	V	vi	I		IV	V	V/vi	vi
	D	E	f♯	A		D	E	C♯	f♯

Now, that C♯ chord is spelled C♯-E♯-G♯, which contains an accidental (the E♯) not found in the key signature of A major (three sharps). This is because that chord is technically in the key of f♯ minor. (It's minor because the chord it resolves to, that vi chord, is a minor chord.)

But wait, you say, why is it a major V? I thought we had modulated to a minor key! The reason is simple: whenever we use secondary dominants, we're talking harmonic minor. Harmonic minor has a raised seven, also known as the leading tone, exactly one half-step below the tonic. Since the V chord is composed of the 5, 7, and 2 scale degrees, if the 7 is raised, it'll be a major triad. Therefore, in harmonic minor, the V chord is major.

Now, there's a leading tone in a major scale, too. Since we'd only ever modulate to a major chord or a minor chord, this means a secondary dominant chord is always major.

So what does a secondary dominant actually do? It gives that feeling of V-I resolution, but resolves to a chord other than the actual I.

[to be finished]