- Hi, in this film,
we're going to discover,
what makes a diminished seventh chord.
And a diminished seventh
chord is rather useful,
because it gives a little bit of colour,
and maybe if you're someone
who's used to using chords,
but you just kind of
basically use the same chords
over and over again,
and you're looking for
something a bit colourful,
the diminished seventh could
be, what you're looking for.
Now you can make a
diminished seventh chord
on any note that you choose.
So, let's take a note,
and see if we can build one.
So, let's start with the note C,
it's as good as anything else,
and basically, a diminished seventh,
piles up minor thirds,
or the equivalent of minor thirds.
Now if you're not quite
sure what I'm talking about
there with minor thirds,
let's do this a different way.
I'll start with C,
and them I'm going to
count up three semitones.
One, two, three.
So the next note is E-flat, or D-sharp.
Let's count up another three,
one, two, three,
and I've now got an F-sharp, or a G-flat.
Let me count up another three.
One, two, three,
and I get to A.
So I've got C, E-flat, F-sharp, A,
but it could be, C, E-flat, G-flat, A.
So there are different possibilities
for how you specifically name the notes.
What we call enharmonic changes,
so this could be D-sharp,
or it can be E-flat.
How do we know?
Well it depends which key
you're in at the time,
but for now don't worry
too much about that,
but you can hear this distinctive sound,
of a diminished seventh chord,
that has these intervals
that we call minor thirds.
And if I move up to C-sharp,
there's another diminished seventh,
here's another one,
and it's a very
distinctive sound isn't it?
And if you've ever seen one
of those old silent movies,
sometimes you get this
diminished seventh thing.
And it's kind of quite dramatic isn't it?
So there we are,
you can build a diminished seventh
on any note that you wish to.
However, diminished sevenths
also belong to keys,
and you may have wondered
what I've got up here on the board.
Well in the key of C major,
I've written a scale of
C major at the bottom,
so C, D, E,
F, G, A, B,
and then I go back to
C for the next octave,
and what I've done is built up the chords,
what we call chords II, II, III,
IV, V, VI, VII,
and to do that,
you put the third note, and the fifth note
above each note of the scale.
You see it I've got a pattern
of three notes on lines,
three notes in spaces,
three notes on lines, three
notes in spaces, and so on.
So chord I is C, E, G,
then there's chord II,
III, IV,
V, VI, VII.
Now if I want to work
out a diminished seventh
in the key of C,
those are all the chords for the key of C,
what I need to do, is to find chord VII.
Now you don't have to write
out all these notes to do this,
you could just think,
well what's the seventh
note in the scale of C.
One, two, three, four, five, six, seven,
so there we are,
and you get your chord VII,
and you'll notice
that these notes are all
ready a minor third apart.
There's the B,
and then one, two, three,
and then one, two, three,
all I've got to do,
is add another minor third on top.
So go another one, two, three,
and I've got my diminished seventh.
So the note that I'm going to
stick on the top of there is,
A-flat.
Now there's nothing to say
it shouldn't be, G-sharp,
but if it was G-sharp,
then it would probably really
be heading for another key,
like A minor or something,
but don't worry about that for now.
But there we are,
a whole series of these minor thirds,
that you just do by counting up three.
There's a diminished
seventh, in the key of C.
And what tends to happen
is the diminished seventh,
is quite often followed, by a chord I.
So if I put this chord up an octave,
you can hear that that chord,
kind of is pulling us
into this chord.
So what I'm going to end up with,
is that one,
followed by this one,
which is chord I.
So you can kind of see how that goes.
So I hope that doesn't
sound too technical,
but I hope it just kind of
gets you into the world,
of the diminished seventh chord,
so you can be playing a piece of music,
and then suddenly you want
a bit of dramatic colour,
and in comes your diminished seventh.
So I could be playing in C major.
And then I could have
a diminished seventh.
And you see it just adds
a little bit of colour to the sound.
So there we are,
that's its function,
to add a bit of colour,
add a bit of drama.
So, have a little experiment with,
the diminished seventh chord.
