- Hi, I'm Gareth Green,
and in this video,
I'm going to try and answer a question
that I know causes some people a lot of confusion,
and it's this.
It sounds like a joke, but it isn't a joke.
What's the difference between a dominant seventh
and a German sixth?
Lots of people say, well, it's the same thing.
Sounds exactly the same.
So why are you trying to make a distinction between the two?
Well, there is a distinction to be made
and it's quite an important one.
So that's what I want to try and get to today.
So on the board, I've written a dominant seventh chord
in the key of D-flat and a German sixth chord
in the key of C
and they sound like the same chord.
So here is the dominant seventh chord in D-flat major.
I've just arranged the notes as A-flat, G-flat,
A-flat and C.
So there's my chord.
But of course the chord is in a kind of close position,
A-flat, C, E-flat, G-flat.
Now, in the case of the German sixth,
well, the chord sounds the same
because it's A-flat C, E-flat, F-sharp.
Ah, so that's the difference.
It was G-flat when I was talking about a dominant seventh
in D-flat.
Now I'm talking about a German sixth in C,
I'm calling that F-sharp instead of G-flat.
So lots of people hear that and say,
well, it's exactly the same chord, isn't it?
So why are we making this distinction between
what would be a dominant seventh in D-flat
and the German sixth in C?
Well, it's about that difference between the F-sharp
and the G-flat.
So we'll come back to that very shortly.
First of all, let's just make sure we understand
what we're talking about.
What is a dominant seventh in the key of D-flat?
Well, a dominant chord is a chord built on the fifth degree
of the scale.
So D-flat major,
D-flat, E-flat, F, G-flat A-flat B-flat C, D-flat.
So the fifth degree of the scale is A-flat.
So the dominant chord is that A-flat with a third above it,
that's C, and a fifth above it, E-flat.
So if I want to make it a seventh,
I'm just adding a seventh above the root, G-flat.
So that's my dominant seventh, my V7 chord, in D-flat major.
Okay.
That's how we arrive at this chord.
How do we arrive at this chord?
Well, the German sixth
is one of three augmented sixth chords.
We've got the Italian sixth, the French sixth,
and then we've got the German sixth.
And the way we find the chords,
just to give you a recipe for this,
if I'm in the key of C.
Okay, so let's start by thinking,
well, the C's my tonic.
In order to form this chord,
I find the lowered sixth above that C,
if I'm in a major key.
So I'm in C major.
The lowered sixth is A-flat.
Above the A-flat, I'm going to form an augmented sixth.
So an augmented sixth above A-flat is F-sharp.
Then I put the tonic in the middle,
the first note of the scale, so that's C.
And that's the basic generic augmented sixth chord.
Now, if I double up that C somewhere,
or even if I just leave it like this,
that's also known as the Italian sixth.
If I add an augmented fourth above the bottom note,
so the bottom note is A-flat,
an augmented fourth above that is D.
So if I put a D into that chord,
so A-flat C, D, F-sharp, that's now a French sixth.
Alternatively, if I add a perfect fifth
above that bottom note, I'll get a German sixth.
So that's the going to be the, A-flat, the F-sharp,
the C that we had, but a perfect fifth above A-flat
at the bottom is E-flat.
And so is the German sixth.
A-flat, C, E-flat, F-sharp.
Okay.
So that's how we arrive at the German sixth.
So hopefully you can see that in fact,
when I calculate a dominant seventh in D-flat,
I'm doing that by a completely different way
from how I calculate the German sixth in the key of C.
We're even in two different keys,
but we end up with a chord that sounds the same.
Now, why then, does it matter about, well, okay,
you've got two chords that sound the same,
what's all the fuss about?
And why does it matter whether you call it G-flat
or F-sharp?
It's the same note, who cares?
Okay, well, it's really about how the chord progresses,
because if this is a dominant seventh in D-flat,
well, it's going to progress in a particular way.
Now, there are conventions about what we do with chords
and harmony, and of course you can break
with these conventions, should you wish to,
but it's always good to know what the conventions are
because there's often a good reason for them.
And one convention about how you resolve a dominant seventh,
what we call voice leading,
is that the seventh falls by step
and the third rises by step.
Okay, let's have a look at that.
Well, the seventh is this G-flat I've got in the tenor part.
So if that's going to fall by step,
then that G-flat is going to go down to F.
The C at the top is third of the chord.
So if that is going to resolve properly,
it's going to rise by a step.
So I've already got those two things that need to happen
if I am going to resolve a dominant seventh,
according to convention.
Now, if I end up with D-flat and F,
I've got two notes of the next chord.
So if I've got D-flat and F,
I've either got the root and the third of a chord I,
a tonic chord, or I've got the third and the fifth
of a chord VI, the submediant chord.
So you'll find in many textbooks,
there's a rule that states,
if you have a V7 chord, you must always follow it
with a chord I or a chord VI.
In fact, that's not the rule.
The rule is this.
The seventh should fall by step,
and the third should rise by step.
The consequence of doing that is that you end up
following chord V7 with a chord I or a chord VI.
Okay,
so just to mop that one up.
Now, if I decide then that I'm going to use a chord I, say,
well, then I've just got to complete the rest of the chord.
So maybe I'm going to have a D-flat in the bass,
and I'm going to repeat A-flat in the alto part.
I could have gone to a chord VI.
Maybe I could have organised the chord differently.
It doesn't really matter.
But the point is, this is one form of a V7 chord
in D-flat major.
The third is rising, the seventh is falling.
So I end up going V7 to I in D-flat major.
But what you're now hearing
is the tonic chord of D-flat major.
And I'm very firmly in the key of D-flat major.
And if I carry on, then I'm feeling very much rooted
in D-flat major.
Okay, let's have a look at this German sixth
in the key of C then.
Now, what are the conventions about what we do with this?
When we resolve one of these augmented sixth chords,
where do we go with that?
Well, the augmented sixth chords tend to progress
to chord V, they're known as predominant chords.
Or sometimes they go to chord I in second inversion,
before they resolve to V.
So you either go straight to the dominant chord,
or you go to I in second inversion,
and that in turn takes you to the dominant chord.
So well, shall we do that?
Just so we've got the idea as to how that would work.
Now, this would be a German sixth in C major or in C minor.
So it could be either.
But for argument's sake, let's say we're in C major.
And before anybody says,
well, how can we be in C major
if we've got A-flat, E-flat and F-sharp?
Because in C major, you don't have any flats or sharps,
that's because those are chromatic notes in C major.
In other words, they're notes that don't belong
to the scale of C major.
Nevertheless, they belong to a chord that functions
in the key or C major.
So it's going on to a chord that belongs
to the key of C major,
even though it's got notes in it that don't belong.
And that's why we call it a chromatic chord.
This is a diatonic chord because it's in the key
of D-flat major.
This is a chromatic chord in the key of C major
using notes in this case that don't belong to C major.
Okay, well, let's see if we can go from the German sixth
to a I in second inversion.
So we'll call that Ic or you will sometimes know this
as a I6/4, if you come from a part of the world
that uses a different convention
with this inversion numbering,
and then we'll go onto a chord V.
Okay, so let's see if we can just make that happen.
Let me just put in some notes here that would enable that.
And we will end up with this.
Okay, so what am I doing there?
Let's just have a little play of that.
Here's the German sixth,
and I'm going on to chord I in second inversion,
followed by chord V.
Now, even though that first chord
has all these chromatic notes,
you can hear that it functions in the key of C major.
So there's the German sixth,
here's the tonic chord in second inversion
followed by the dominant chord.
And now I'm very much in C major aren't I?
So that's very much here.
The dominant seventh is functioning in D-flat major.
Here, the German six is functioning in C major.
So the two chords sound the same,
but function very differently.
This is a diatonic chord that has particular rules
of engagement about how it resolves.
And those rules really result in you moving to a I
or to a VI,
but the German sixths in C major,
you've got a chromatic chord using notes
that don't belong to the key.
And that has also rules of engagement
about how that resolves.
So you can see that even though you start by listening
to a chord, that sounds exactly the same.
When you hear that chord in no context at all,
you don't know if that's a V7 in D-flat major
or a German sixth in C.
but how they resolve and how they function
within the context of the music matters hugely
and takes them in a very different direction.
So a dominant seventh in D-flat goes on to a tonic chord
in this case in D-flat,
whereas that German sixth in C major going onto a chord I,
a tonic chord in second inversion followed
by a dominant chord, a chord V and then carries on
in C major.
So, it's about enharmonics.
You know, what's an enharmonic?
Means it sounds the same, but it looks different.
F-sharp sounds the same as G-flat,
but it looks different.
And the implications of it looking different
is that it functions in a very different way.
So it would be wrong to write a German sixth in C
with a G-flat in it, in the same way that it would be wrong
to write a V7 in D-flat with an F-sharp in it,
which is why when you're writing these things,
that's actually quite important.
Now, of course, this opens up all sorts of opportunities.
You might, for example,
be playing a piece of music in C major
and be solidly in C major.
Then you might say, oh, I'll have a German sixth
and carry on in C major.
Or you might say, well, I'll have a German sixth,
but you know what?
Then I'll make an enharmonic change
and I'll call that F-sharp, G-flat,
and then I can carry on in D-flat major.
So it does give us opportunity to shift keys and so on.
We can play with that enharmonic difference,
but I'm hoping that this has clarified
that there's a very clear distinction
between a dominant seventh and a German sixth.
Well, if you've enjoyed this video,
we've got other videos on the channel
that explore in a bit more detail,
how these augmented sixth chords work
that you might want to have a look at,
but also many courses on our website,
www.mmcourses.co.uk.
So have a look there because there's lots more on theory.
Our advanced theory course, for example,
really goes into the detail of harmony.
There's a Bach chorale course.
There's all sorts of other stuff on there.
So have a look there and while you're on that home page,
you could also click on a link to Maestros
and that will tell you all about our global community
that we have at Music Matters.
All sorts of perks, including discounts
on our online courses and opportunity to meet
once a month for our live streams,
to interact with other people in the group
to submit compositions, performances,
for one-to-one feedback on that stuff.
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So if you want to do that,
have a look at Maestros and you'll discover
all that we have to offer there.