we need to create these scales in quite an abstract theoretical way.

Now it's a good time to actually go back

and relate this to music in more general terms.

So if you had a piece of music that just used the notes of C-Major.

That's the notes of the C-Major scale.

We could say that this music is in the key of C-Major.

>> And if we had the notes of the G-Major scale; with that

F-sharp, we can say that this is in the key of G-Major.

>> So what do we actually mean by key?

Well, it's quite a complex term really, and it relates not only to the

notes that are available to us, as drawn from the scale, but also to the

way that we subconsciously hear the way that these notes work with each other

and react with each other and the

relationship that exists between each of these notes.

>> So, that feeling in G-major.

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We have a sense, that out of all these notes.

[MUSIC]

G has got a kind of gravity for us.

[MUSIC]

G pulls us home.

G is our tonic.

>> Yeah, we could say that when we are playing

a piece of music that uses these notes; when we

arrive back at G, there's a feeling of completeness or

that we're at rest; it's the home note if you like.

So, when we are talking about scales

and keys, they are sometimes confused as terms,

and what we really mean when we are

talking about scales is this sort of ordered.

[MUSIC]

String of notes.

When we're talking about key, just to reiterate, it is this relationship and

the feeling that pulls us back to the tonic when we feel at rest.

>> Okay, so, if you did the exercise that we used in the last section where we

started on D, you'll note that we got

in D-major, we got an F-sharp and the C-sharp.

[MUSIC]

So, if were looking at piece of music written down

in a score, how would we know what key it's in?

What we might want to do is look to see whether any of the Fs

are sharpened, and we say, yes, all the Fs have got a sharp next to them.

And we see that, oh, also, all the Cs have got a sharp next to them.

In the context of everything we've just said, so far in this lecture, it would

make a lot of sense to say, oh, this piece of music's probably in D-Major.

>> So given that we know in this case

that we're going to have every F-Sharp and every C

as a sharp, it might make sense for us

to know this information up front, right at the start.

And the convention that we've got for this, we call 'key signatures'.

So by announcing what we're going to have in terms of sharps or

flats right at the very start, it does a couple of things for us.

So firstly from a musical point of view, what it does is it, it

gives us an indication of where the tonic is, what's going to be most important.

And also the relationship that exists between the notes in this key.

But also, just from a visual point of view,

what it does is it really tidies things up.

So that no longer do we have the need for every F and every C to

have a sharp in front of it to say that these are going to be F and C-Sharp.

Actually, we see this at the very start by means of the key

signature, and we take it as

read throughout unless we are signaled otherwise.

>> There's additional on the website that'll help you learn more about the

conventions of notation because what we are talking about here, is the idea of

graphically representing, for people to read and to write with, all of these

concepts and terms that we're, that we're introducing to you for, for music theory.

>> So key signatures are used to tell whoever's looking

at the music, what key the music's in and to

do so by signaling, which notes are going to be sharp

and which notes are going to be flat; from the outset.

There's a really logical way for writing key signatures.

And also, if we're looking at key

signature and determining what key it signifies.

>> We call this the circle, or sometimes the cycle of fifths.

Let's start with C.

C, as we know, C-Major is signified by having no sharps and no flats.

That's the key signature.

G, however, contains one sharp.

>> F sharp.

>> F sharp.

>> G.

>> And D, has got two sharps; it's also got an

F-Sharp, and now it's also got a C-Sharp on top.

>> So if we look at the cycle of fifths, we can see when

we look at the key signature for C, there are no sharps or flats.

And this makes sense because when we play C-Major and we're

looking at it on the piano, we only use the white notes.

If we look at the next stage round clockwise, we see

that we're looking at G-Major, which is signified by having an F-Sharp.

If we look at the next stage again, clockwise.

We see that we've got D-Major, and that this is an F-Sharp and a C-Sharp.

>> So you'll note, notice the cycle of

fifth is proceeding literally stages of a fifth.

C, D, E, F, G.

>> And then we've got G, A, B, C, D.

>> Each stage includes five note names forwards.

And each stage includes one additional sharp as we go around the circle.

Okay, so we've looked at our circle, the circle of fifths moving

around clockwise where each stage takes on five notes for further forward.

Okay, what happens if we look anticlockwise?

The results of this is that we're, in

fact, going, moving in fourths instead of fifths.

So, we're starting at C again.

>> So, let's start with C and move around in fourths.

So if we go from C, we go to the fourth note of C-Major.

C, D, E, F.

So we're going to start on F.

Now just to illustrate this really, let's apply the major scale pattern to F.

Okay, when we do that we get F, G, A, B-Flat, C, D, E, F.

So what we can say now is that the scale of F has a B-Flat in it.

One flat.

>> One flat.

One B-Flat.

Clockwise sharps, anti-clockwise, the first thing we

notice is that we're introducing one flat.

Okay, so we might be able to guess where this is going.

Starting from the F, let's travel another fourth around the circle.

So we're going anticlockwise.

>> F, G, A, B-Flat.

>> B-Flat.

So, we can take our B-Flat as our tonic

now, and we're going to apply our major scale pattern.

We've got B-Flat, C, D, and a semitone takes

us to E-Flat, F, G, A and back to B-Flat.

So what we've found now is we've got a

B-Flat and an E-Flat, so we've added an extra flat.

for an extra step, around the circle, just as we did for sharps.

Therefore, B-Flat has B-Flat and E-Flat.

So it's all fair and well, then, when we're looking at the circle of

fifths to say when we move around

clockwise, we're going to add one extra sharp.

Or when we move anticlockwise, for each step, we're going to add one extra flat.

But it's not really enough information.

We need to know, which extra sharps and

which extra flats we're going to add for each step.

So we could really go back to the keyboard and

work it out from first principles, and for each new

tonic, we build a major scale, and we work out

which extra sharps we've got and which extra flats we've got.

But that's time consuming, it's a bit of a

pain; we need to remember lots of different information.

Actually, having some sort of mnemonic device for the order

that sharps and flats occur is probably going to be quite useful.

And it's really common for people to learn it in this way.

So, and good pneumonic advice for the order that the sharps occur.

Father Christmas gave Dad an Electric Blanket.

>> So, that's F, C, G, D, A, E, B.

>> You

could also say, Father Charles Goes Down And Ends Battle.

That's a very common one to hear people talking about.

>> Okay, so there's two.

You could make your own up.

Now, this being the circle of fifths, with all the patterns inherent

in that, when we go anticlockwise and start introducing flats, you might

not be that surprised to find out that the order in which

flats occur, is actually the same sequence as the sharps but in reverse.

B, E, A, D, G, E, C [LAUGH] C, F.

So two sentences that we could use to try and remember that sequence,.

>> Well, we've got Blanket Explodes And Dad Gets

cold feet, which is the reverse of the Father Christmas one.

>> Or Battle Ends and Down Goes Charles' Father.

So, we now know that if you see a key signature at the start of a piece of

music, and it's got four sharps in it; those

four sharps have to be F, C, G and D.

And we know that if you see a key signature with three

flats in it, they're going to have to be B, E and A.

>> So we've been talking about sharps and flats within keys.

So that's to say that we've been talking

about the sharps that belong to a particular key.

Or the flats that belong to a particular key.

But what happens if we want to use a note that's out

with the pool of not available to us in any given key?

So say we were in G-Major.

We wanted to use a B-Flat for instance.

We know this isn't part of the key signature.

But there's absolutely nothing wrong with using

a B-Flat in the overall context of G-Major.

If we do this, if we use a sharp or a flat in a place that we don't

expect that based on the key signature, we call

these accidentals; let's say it's absolutely fine to use these.

We just need to be aware of some conventions

surrounding them, so we can actually use them, talk about them accurately.

Have a look at the example:

>> We can see that in this example, the music got a

key signature of one sharp, so we know it's going to be

an F-Sharp, and we know that this signals G-Major; however, there are

notes here that don't belong to the key; there are some accidentals.

[MUSIC]

As we work from left to right, looking along the example, we can see that

there's a sharp sign in front of the third note, meaning that this is a G-Sharp.

[MUSIC]

>> And looking further along, we notice a flat in front of the B.

Making it a B-Flat.

[MUSIC]

Now, just in front of the next B, we see a symbol that we haven't seen before.

[MUSIC]

This is another type of accidental, and we call it a natural.

Its purpose is to cancel out the sharps

or flats that have just previously been shown.

>> One thing that we need to mention at this point is

that when an accidental is used, it's actually effective for the whole bar.

We'll discuss what bars mean more next week, but really what we

mean is until we see the next vertical line across the stave.

So the second bar, we see a B-Flat.

And this means that any other B in that bar is also a flat.

The natural sign in front of the last note in this bar actually cancels

out the flat, meaning that this particular note is to be played as a B-Natural.

That is to say that it is no longer a B-Flat.

And again, although this is the last note in the

bar, this instruction lasts right to the end of the bar.

If we can look at the next bar, we see a natural in front of the F.

Again, this cancels out the F-Sharp in the key signature.

And it means that this note is to be played as an F-Natural, not an F-Sharp.

>> Have a look at additional material on on the website.

We've included some practice questions to help you get to grips with this.

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