Key Signatures - Major Keys

KEY SIGNATURES: MAJOR KEYS - “The only sentence you will ever need to learn”

Key signatures will ALWAYS be identical on both staves.  Yes, it is possible for them to be different - its called "polytonality" [literally "many key signatures"] or "bitonality [literally "two key signatures"] - we’ll look at that later.  You will need to be able to read them and write them in either clef, remembering that the letter names have different positions on each.

Learn this sentence:

Father

Charles

Goes

Down

And

Ends

Battle

Read downwards it is the order of sharps, so the key signature that has one sharp WILL ALWAYS BE an f sharp.  Four sharps would be f, c, g & d.  Identifying the key note [the tonic or first note of the scale] of the MAJOR SCALE is easy from a key signature.  Remember this: the LAST SHARP in the key signature is ALWAYS the SEVENTH NOTE of the scale [the one before the key note or tonic].  So, for example, the key signature of f sharp: f sharp would be the seventh note, going one step up gives you a G = G major.  The four sharp signature given above, the last sharp is d ["Father Charles Goes Down]", going one step up to E = E major.  This is true of ALL key signatures containing sharps.

For flat key signatures, go back to the sentence and read it BACKWARDS:

Battle

Ends

And

Down

Goes

Charles'

Father

This is the order of flats.  So the key signature with two flats will be b flat and e flat.  Five flats would be b, e, a, d, g.  Identifying the key note is also easy for flats, just different.  The SECOND LAST FLAT IS the key note. So, for two flats, the second last flat is b flat = B flat major.  For the five flat key signature above, the second last one is D flat = D flat major.  This is true of ALL key signatures containing flats [almost - see below].

Learning these, you can work out every major key that exists, with two exceptions, which you must remember:

[a] C major has no sharps or flats, so you can't apply either rule to it.

[b] F major has only one flat, so it doesn’t have a second last flat.  However notice that its last [only] flat is the fourth note of the scale, and in all the other flat key signatures the LAST flat will be the fourth note of the scale too.  You could work them all out that way - if you do, remember "SHARP SEVENTH note, FLAT FOURTH note".

You can also apply those rules in reverse to work out a key signature from any given tonic note.  What would the key signatures of the scales commencing on these notes be:

D major

B major

B flat major

A major

A flat major

E flat major

Finally, I've said "MAJOR" scales here.  MINOR keys are different, in that you've got to do all this, but there's another step involved - we'll worry about that another time.

Here's our worksheet:

https://docs.google.com/open?id=0B9JdpU-tw7FuWFBrVVFQa0dkeXM