15 key signatures to 15 diatonic scales

15 key signatures to 15 diatonic scales

We know the 15 diatonic scales.

Each has a key signature.

G has one sharp in its diatonic scale and the same sharp in its key signature.

The diatonic scales are matched to their key signatures below.

Sharp notes enter in order F#, C#, G#, D#, A#, E#, B#. You remember this sequence from the diatonic scales. Flats enter in mirror order Bb Eb Ab Db Gb Cb Fb.

Know the C# and Cb key signatures and you know all key signatures.

C# is the key signature of 7 sharps.

Cover the right most sharp.

You now have the key signature of F# (6 sharps).

Cover two sharps to the right.

You now have the key signature of B (5 sharps).

Now start with a clean stave (no key signature). A sharp on F# is the key signature of G. Another sharp over C# changes the key signature to D. Keep adding sharps in this sequence to change the key signature.

Key signatures are building blocks to each other.

You must be able to recognise and write every key signature in every clef.

Flat key signatures change height but otherwise stay constant through all clefs. They change height to match the names of the notes. Bb is middle line of the treble clef and second space up on the alto clef.

Sharp key signatures similarly change height through the treble, bass and alto clefs. On the tenor clef the standard pattern won't fit. The pattern is mirrored so all sharps in the pattern can fit on the clef.

 

 

The diatonic scale on the stave

There are two ways to write a diatonic scale on the stave.

With a key signature

Without a key signature

With a key signature you establish the accidentals at the start of the stave. Without a key signature you define each accidental as it is played.

The key

In the key of G, F# is normal. The key signature of G is appropriate.

To write a melody without a key signature you define each accidental as it is played. Scroll down to the next illustration. Press the midi buttons to hear each illustration. Can you hear the difference? No. Can you see the difference? Yes.

The melody with a key signature looks cleaner and more informative. The key signature tells the musician to expect F# and it tells the musician which key the music is in.

We can distort the look of the melody by changing the key signature. This melody sounds the same as the two above but it looks awful. It is still in the key of G. The key signature has changed to Ab.

Now shift each note up a semitone. What have we done? We have changed the key. We have changed the sound. The melody is now in the key of Ab A melody in the key of Ab looks right in the Ab key signature.

Accidentals on the stave

In the key of D, F# and C# are expected. When the key signature is D each unaltered F is F# and each unaltered C is C#.

To override the key signature you place an accidental at the note-head.

The accidental in front of the note-head holds true:

• for the line or space it is on
• until the next barline
• or until it is changed by another accidental

Take a close look at this example. The barline is the vertical line cutting through the stave at regular intervals. The barline measures the pulse.

The music starts on AB The second note is A natural. Remember the rule: For the line or space it is on. The higher A is natural until we make it flat.

The 4th and 8th notes are F#. We must repeat the sharp accidental to repeat F# because high F# is on a different part of the stave to low F#.

The last note before the first barline is AB We do not put a flat in front of the note head. Trace the AB space from the first note on the stave to this note. Remember the rule: For the line or space it is on until the next barline.

We had F# in the first bar. We want F natural in the second bar. This is easy to achieve. We do nothing. F# in the first bar lost its power at the barline.

Clarity

How do we define success? When a professional musician can play your music comfortably at first sight.

How to we achieve success? We clarify ambiguous accidentals. A correctly written note may have no accidental at the note-head but still cause confusion. You don't want rehearsal time wasted on such questions as “Is that natural or sharp?” Arguments may spark along the lines of ... "Musically it could be ..." and "Yes, but I think that's a printer's error." If half the musicians play C natural and half play C# together you are in trouble.

Study this example. Is the first note of bar 4 C natural or C#?

If you mean C# write C#.

If you mean C natural put a natural accidental in brackets in front of the note head. By putting the accidental in brackets you are confirming the key signature.

The key signature

tells the musician which key the music is written in and which accidentals (flat, natural, sharp) are normal to the stave.

Standard accidentals at the note head

tell the musician that this note is altered from the key signature or altered again in the bar. Do not go mad putting accidentals in front of every note head. Learn the rules. A well-written melody is one a professional can sight read perfectly at first glance. Aim to please the professional musician.

Accidentals in brackets at the note head

confirm the key signature where ambiguity may otherwise arise. Don't bracket accidentals which shouldn't have brackets. The accidental in brackets is always true to the key signature. It is a reminder of the key signature, never contrary to it.

Accidentals, the principal name

Now we know our diatonic scales and we know our key signatures. We are ready to believe that F# is more common than Gb. The more common a name the more familiar it is to us. The common name is the principal name.

Recall how 9 of our 12 notes have two names.

C# Db

D# Eb

F# Gb

G# Ab

A# Bb

C B#

D

E Fb

F E#

G

A

B Cb

Well let us do some detective work. How many key signatures is F# in? 7. How many key signatures is Gb in? 3. F# is the principal name of the F# / Gb enharmonic pair.

Enharmonic names	The enharmonic name that appears in the greater number of key signatures is the principal name		Principal name
B# C	B# is in 1 key signature	C is in 7 key signatures	C
C# Db	C# is in 6 key signatures	Db is in 4 key signatures	C#
D			D
D# Eb	D# is in 4 key signatures	Eb is in 6 key signatures	Eb
E Fb	E is in 7 key signatures	Fb is in 1 key signature	E
F E#	F is in 7 key signatures	E# is in 2 key signatures	F
F# Gb	F# is in 7 key signatures	Gb is in 3 key signatures	F#
G			G
G# Ab	G# is in 5 key signatures	Ab is in 5 key signatures	Ab
A			A
A# Bb	A# is in 3 key signatures	Bb is in 7 key signatures	Bb
B Cb	B is in 7 key signatures	Cb is in 2 key signatures	B

C#

Eb

F#

Ab

Bb

C

D

E

F

G

A

B

 

Key signatures and accidentals

This chapter translates the diatonic formula into music notation. Be sure to read pages 1 to 12 before continuing.