In today’s lesson, we’ll be exploring how to play dominant 7th chords. These appear for the first time in your technical tests for grade 5 RCM. And they’re the first 4-note chord you’ll need to learn if you’re following this examination system.
Since they’re 4-note chords, the actual playing part can be a bit of a challenge at first. If your fingers aren’t used to configuring like that, it can take some getting used to.
Today I’ll show you what dominant 7th chords are and how to figure them out – and, of course, how to play them.
Let’s get started!
What are dominant chords?
What are dominant 7th chords?
Let’s back up a moment and figure out what dominant chords are.
The word “dominant” refers to a certain Roman numeral – the “V”, or 5. Another word you might have heard before, “tonic”, refers to the “I”, or 1. These Roman numerals refer to scale degrees.
All I mean by that is…
If your piece is in the key of C, the tonic is C (note #1) and the dominant is G (note #5). If you’re in the key of F, the tonic is F and the dominant is C.
Tonic = I = 1
Dominant = V = 5
In the key of G:
Tonic (I) = G
Dominant (V) = D
One more, in the key of E:
Tonic (I) = E
Dominant (V) = B
So the “dominant” can either be referring to a single note, or a chord starting on that note. For example, the dominant chord in the key of C would be a G major chord.
The dominant chord in the key of F would be a C major chord.
Adding the 7th to the dominant chord
Now that we’ve figured out what the dominant chord is, let’s figure out what it means when we say “dominant 7th”.
It’s actually pretty much what it sounds like. You add the (lowered) 7th note of the chord.
If your chord is the dominant 7th of C, it’s going to be a G7 chord. A G7 chord formula looks like this:
1 3 5 b7
(the b7 just refers to the fact that the seventh note is lowered a half-step from what it would be in the scale).
In a G scale:
1 (G) 3 (B) 5 (D) b7 (F)
So the dominant 7th of C would be: GBDF.
Let’s figure out another one!
The dominant 7th of F. First of all, what’s the dominant chord of F? It’s the fifth note, so it’s C. We need to figure out a C7 chord.
The formula, again, is: 1 3 5 b7. If we plug that into C scale, we get these notes:
1 (C) 3 (E) 5 (G) b7 (Bb)
Let’s do one more: E. What’s the dominant 7th of E?
Well for starters, the dominant chord is B (V). So we need to figure out the B7 chord.
1 (B) 3 (D#) 5 (F#) b7 (A)
If you don’t have all of these scales memorized, you can think of it in terms of semitones. The distance between 1 3 5 b7 is:
4 half-steps / 3 half-steps / 3 half-steps
So if we were trying to figure out a C7 chord, we would start at C, go up 4 half-steps (E), go up 3 half-steps (G), and go up 3 more half-steps (Bb).
You can also use a scale chart if you have one.
How to play dominant 7th chords
Like triads, there are two ways to play dominant 7th chords: solid and broken.
For both types of chords, at a grade 5 level, you’re expected to play hands separate 1 octave. Let’s look at how to do solid in the right hand, and left hand, in turn.
And let’s take a look at broken chords.
The fingering for these chords is really up to you – whatever fingering allows you to play it smoothly and easily. In general, if you follow this rule you’ll do fine:
-Don’t use your thumb on a black key (or your 5th finger if you can help it)
That’s pretty much it. You can use 1-2-3-4 for most of the chords, whether they’re solid or broken. Experiment with what works for you.
As I mentioned earlier, these chords are going to feel pretty awkward and clunky if you’ve never played 4-note chords before. It took me weeks before I felt like I could actually play them half-decently.
The 3-to-4 chord learning curve is a little steep, but once you’ve made it to the other side, you’ll have no problem with any type of 4-note chord.
Enjoy – and we’ll take a look at all the technical requirements for grade 5 RCM shortly so you can see these in action in full.