Secondary Dominant Chords « Guitar Teacher

Secondary Dominant Chords

Posted on May 6, 2009 by MD

We’ve already been over dominant chords. If you missed that make sure you get up to speed here. Today we will be taking the next step and look at some secondary dominants.

Review

First lets recall some things about dominant seventh chords:

A dominant seventh is made up of a major triad with a minor 7th added.

In a major scale the fifth tone of the scale can become the root of a diatonic dominant seventh chord for that key.

In minor keys we sometimes will raise the seventh of the key by one half step (harmonic minor) so the the seventh chord build on the fifth of the scale is in fact a dominant seventh (if not it would be a minor seventh).

The diatonic dominant seventh contains the key defining tritone, the third and seventh of the chord (seven and four tones of the key respectively)

An Analysis of Brahms’ Lullaby

The easiest way I can explain what exactly secondary dominants are are to give an example. So we’ll start with an analysis of a piece you have all heard: Brahms’ Lullaby. It’s in A major, so lets quickly break down all the diatonic chords in A major:

A Major Diatonic Chords

G#	A	B	C#	D	E	F#
E	F#	G#	A	B	C#	D
C#	D	E	F#	G#	A	B
A	B	C#	D	E	F#	G#
Amaj	Bmin	C#min	Dmaj	E7	F#min	G#dim7
I	ii	iii	IV	V	vi	vii

Now lets start the analysis:

Measures 1-7

It starts out simply enough. The first to measure establish the tonic as A Maj (A C# E). In the fifth measure it moves onto the vi chord, F# min (F# A C#). Then in the 7th measure it starts to get a little weird. The first chord is a iii chord, C# min, but the the chord on the third beat of the measure is a mystery (its not that big of a mystery if you read the previous paragraphs).

Lets break down that chord a little. It contains four notes: [G# B# D# and F#, hint- remember the key signature]. That would make the chord a G# dominant 7 chord. But the dominant 7th of A maj is E dom7, so how can that G#dom7 be in there? Look at the next measure for the answer:

Measures 7 and 8

The next chord is also a iii chord. So we have a C# min chord, then a G#dom7 chord, then a C# min chord again. If we think about the C# harmonic minor scale [ C# D# E F# G# A B# C#], we see that the dominant 7th in this key is G#dom7. So the mystery chord is in fact the dominant 7th chord of C#min. We would write this as V7/iii or V7 of iii ( said “five seven of three”). In the piece it is as though for a moment C# becomes the tonic for. The chord is called a secondary dominant chord because it is a dominant chord that is borrowed from one of the notes of the A major scale. In this case Brahms’ barrows the dominant of C#, the three of A maj.

Measures 8 – 15

In measure 9 we move back to the tonic, A maj, with a simple V7- I progression. Then comes another mystery chord [A C# E G]. At first glance this chord may look like a I7 chord. But if it was an Amaj7 chord it would have a G# not a G natural. It is instead an Adom7, the V7 of DMaj. If we look at the next chord it is in fact a D major chord which is a IV chord in A maj. So mystery chord “A” is V7/IV. It is the dominant of the fourth tone in the A maj scale, which makes D a “mini-tonic” for a few measures. Next comes mystery chord B, [B D# F# A]. At first glance it may look like a ii chord in A maj. But it contains a D# so it is not. It is instead a Bdom7, which is the dom7 of E Maj, the V of A maj. So mystery chord B is V7/V. I’ve posted a complete analysis of the first 15 measure below (click to enlarge).