Key signature, in musical notation, the arrangement of sharp or flat signs on particular lines and spaces of a musical staff to indicate that the corresponding notes, in every octave, are to be consistently raised (by sharps) or lowered (by flats) from their natural pitches.

1. MUSIC
PRESENTATION

2. CONTENTS
What is Key Signature?
What are the Types of Key
Signature?
What is Enharmonic Spelling?
What is Enharmonic Notes?

3. KEY SIGNATURE COMES RIGHT
AFTER THE CLEFT.

5. KEY SIGNATURE

9. What a Natural Sign Looks Like (How to Draw)
So what does this sign look like? Here we go: ♮. It
looks almost like a sharp sign, but some of its lines are
not as long. The space in the middle of this sign is
placed on the exact line or space as the note head it
affects. Its height is about three staff spaces.

11. What Are Sharp Notes in Music?
Sharp notes are notes that sound a semitone
higher than notes that appear on the lines and
spaces of a musical staff.
As an example, the note G is represented on the
second line of the treble clef staff. The note G-
sharp is indicated with that same note head with
a # symbol placed to the left of it.
The # symbol universally indicates a sharp note.
It tells a player to sound a pitch half a tone
higher than the written note. For instance, the
following image indicates the note C# on the
treble clef.
C sharp diagram.

14. What Are Flat Notes in Music?
Flat notes are notes that sound a semitone lower than notes that appear
on the lines and spaces of a musical staff.
•As an example, the note B is represented on the third line of the treble
clef staff. The note B-flat is indicated with that same note head with a ♭
symbol placed to the left of it.
•The ♭ symbol universally indicates a flat note. It tells a player to sound a
pitch half a tone lower than the written note. For instance, the following
image indicates the note A♭ on the treble clef.

25. Enharmonic Spelling
 is the practice of rewriting a note so that it looks
different on paper but would be played by the same key
on a piano (for instance, C! # and D! b). Although modern
musicians may think of these pitches as equivalent, the
practice of enharmonic spelling was unusual before the
rise of equal temperament because two such pitches
might not be exactly the same. (In keeping with this
earlier tradition, string players and singers are often
advised to perform sharp notes slightly higher and flat
notes slightly lower.) It is useful to differentiate recognize
three forms of enharmonic spelling: respelling for the
sake of convenience, misspelling, and modulation through
reinterpretation.

26. Respelling for the sake of convenience
 Respelling for the sake of convenience Sometimes a composer wants to modulate
according to a particular key relationship. For instance, perhaps there is a prominent
motive involving b 6 ^!, so it seems desirable to modulate to the key of b VI. Usually
this is easy: if the composition begins in D, the music can simply modulate to B! b.
However, what if the composition begins in D! b? Suddenly we are faced with the
prospect of modulating to B! bb — a key that few, if any, performers would like to
read for any length of time. Clearly it would be advantageous in this case to respell
B! bb as A. (Despite the respelling, it is still customary to identify A as b VI.) Similarly,
suppose that the composition emphasizes rising major thirds, so the composer
decides to modulate from I to III. There’s no problem modulating from E! b to G, but
if we start in E we certainly wouldn’t want to end up in G! # . We’d much rather
respell the passage in A! b (which, as before, we would identify as III despite its
spelling). These cases are fairly easy to recognize: there is generally a key change
where flats are replaced by sharps, or vice versa. The passage tends to be relatively
long (otherwise the spelling change probably wouldn’t be worth the effort), and
usually all notes of the passage are respelled. Notice that the spelling change is
strictly for the sake of convenience; it is not technically necessary, and it will not
affect your analysis.

27. Misspelling
 Misspelling Sometimes a composer enharmonically respells part of a chord — often
only a single note. The respelled note is typically less common than its enharmonic
replacement (for instance, E! # may be replaced by the more familiar F), so
presumably the change is intended to facilitate reading by the performer. Although
this seems like a simple idea, enharmonically respelling part of a chord can cause
analytical confusion because the chord structure looks significantly different.
Consider, for instance, a German augmented-sixth chord in C! # minor, as shown on
the next page. Spelled correctly, the chord should contain an F! ‹ , but a composer
might choose to write the more common G! n instead. Suddenly the chord appears
to be a dominant seventh rather than an augmented sixth! However, we can tell by
the chord’s resolution that it is, in fact, a misspelled Ger +6. Notice that the G! n
goes up to G! # , just as the correct F! ‹ would have resolved. Had the G been a
legitimate seventh, it would have resolved down by step (presumably to F# ).

28. Modulation through enharmonic
reinterpretation
 Modulation through enharmonic reinterpretation. As we saw above, a German
augmented-sixth chord might be misspelled as a dominant seventh chord. However, what
if the chord in question had truly resolved as a dominant seventh?
 A composer might modulate from C# minor to the remote key of D major using this chord
as a pivot. Unlike most pivot chords, notice that the chord cannot be spelled correctly in
both the old and the new key: the composer must choose between F! ‹ and G! n .
Although these spellings are equally correct under the circumstances, composers usually
prefer to show how the chord works in the new key so that the resolution looks
appropriate. The chord that is most often exploited for the purposes of modulation
through enharmonic reinterpretation is the fully diminished seventh chord (vii°7).
Because this chord is entirely symmetrical (chord members are consistently separated by
exactly three half steps), it can be respelled with any chord member as the root and
resolved accordingly.

39. Enharmonic Keys
The keys at the bottom of the circle of fifths have two names because they
are enharmonic equivalents. The principle of enharmonic equivalence is the
same for keys and scales as it is for individual pitches. Enharmonic keys occur
when the same set of pitches can be indicated with either sharps or flats. For
example, the key of D-flat has 5 flats and the key of C-sharp has 7 sharps.
Just as the pitch D-flat is the same as C-sharp, so are the sets of pitches in
their respective keys. If we look at each note in the D-flat and C-sharp major
scales, we can see that each scale degree is enharmonically equivalent.
Scale
Degree:
1 2 3 4 5 6 7 8(1)
D-flat
Major
Scale:
D-flat E-flat F G-flat A-flat B-flat C D-flat
C-sharp
Major
Scale:
C-sharp D-sharp E-sharp F-sharp G-sharp A-sharp B-sharp C-shar

40. Parallel and Relative Keys
We learned about the concept of relative and parallel relationships
in the section on scales, and these relationships apply equally to
keys. In the circle of fifths above, the keys are aligned in slices
according to their key signatures. Since two keys are considered
relative if they share the same collection of pitches, the major and
minor keys that are aligned in each slice are relative
keys (examples: G major and E minor, E-flat major and C minor).
Keys in the circle of fifths that have the same tonic
pitch are parallel keys. In the table below, you will
see the key signatures required to have a major or
minor key for each tonic pitch.

41. THANK YOU!!!