What a key signature is
A key signature is the group of sharps (♯) or flats (♭) written right after the clef at the start of every line. It applies to every note with that letter name, in any octave, for the whole piece, and it shows the key. To see why each key has its own sharps or flats, read the major scale.
The order of sharps and flats
| Order | |
|---|---|
| Sharps ♯ | F, C, G, D, A, E, B |
| Flats ♭ | B, E, A, D, G, C, F |
A classic way to remember: Father Charles Goes Down And Ends Battle. Read it backwards for flats: Battle Ends And Down Goes Charles' Father.
Finding the key with sharps
Take the last sharp and go up a half step. That's the major key.
- 1 sharp (F♯): F♯ + half step = G major.
- 2 sharps (F♯, C♯): D major.
- 4 sharps (…, D♯): E major.
Finding the key with flats
The second-to-last flat is the name of the major key.
- 2 flats (B♭, E♭): B♭ major.
- 3 flats (B♭, E♭, A♭): E♭ major.
- The exception is 1 flat (B♭): it's F major.
No sharps or flats means C major (or A minor).
Major or minor?
Every key signature is shared by a major key and its relative minor, 3 half steps lower. G major and E minor both have one sharp. More in the minor scale.
- Look at the last note and last chord: it is almost always the key.
- Look for the raised 7th of the minor key: in E minor you'll see D♯.
- Listen: major usually sounds bright and open, minor darker or more serious.
Now put the theory into your fingers
In Dedilhado Vivo you learn flute, guitar, violin or piano by seeing each finger on the screen, and the app listens to you play through the microphone.
Practice theory in the free appChart of all keys
| Key signature | Major key | Relative minor |
|---|---|---|
| 0 | C major | A minor |
| 1♯ | G major | E minor |
| 2♯ | D major | B minor |
| 3♯ | A major | F♯ minor |
| 4♯ | E major | C♯ minor |
| 5♯ | B major | G♯ minor |
| 6♯ | F♯ major | D♯ minor |
| 7♯ | C♯ major | A♯ minor |
| 1♭ | F major | D minor |
| 2♭ | B♭ major | G minor |
| 3♭ | E♭ major | C minor |
| 4♭ | A♭ major | F minor |
| 5♭ | D♭ major | B♭ minor |
| 6♭ | G♭ major | E♭ minor |
| 7♭ | C♭ major | A♭ minor |
F♯ and G♭ major sound the same (they are enharmonic), as do C♯ and D♭, and B and C♭. The chords in each key are in diatonic chords, for example G major.
Key signature vs. accidentals
- A ♯, ♭ or ♮ written next to a note is an accidental: it lasts until the end of the measure.
- A natural ♮ cancels the key signature for that measure.
- In the next measure the key signature applies again.
Frequently asked questions
What is a key signature?
The set of sharps or flats at the start of the staff. It applies to every note of those names throughout the piece and shows the key.
What is the order of sharps?
F, C, G, D, A, E, B. Flats are the reverse: B, E, A, D, G, C, F.
How do you find the key from the key signature?
With sharps, go up a half step from the last sharp. With flats, the second-to-last flat is the key (one flat is F major).
What key has one sharp?
G major, or its relative E minor.