Lesson 36 / 41 8 min
Sharps, flats and key signatures
Accidentals, naturals, double sharps and flats, the order of sharps and flats, every key signature and key changes.
So far most notes have been natural — the white keys of a piano. This lesson adds the notes in between, and the shortcut that keeps sheet music from filling up with symbols: the key signature.
Accidentals
An accidental is a symbol written just before a note that raises or lowers it:
| Symbol | Name | Effect | On the guitar |
|---|---|---|---|
| ♯ | Sharp | Raises a half step | One fret higher |
| ♭ | Flat | Lowers a half step | One fret lower |
| ♮ | Natural | Cancels a sharp or flat | Back to the plain note |
| 𝄪 | Double sharp | Raises a whole step | Two frets higher |
| 𝄫 | Double flat | Lowers a whole step | Two frets lower |
Some notes move to another string: B is the open B string, and since there's no fret below 0, B♭ is played on the 3rd fret of the G string.
Here is the chromatic scale — every fret, one after another — going up with sharps and coming down with flats:
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C♯ and D♭ are the same fret — two names for one sound (they're enharmonic). The name depends on the key and on where the melody is going.
Double sharps and double flats are rare, but they exist so a note keeps its letter name in keys with many sharps or flats. F𝄪 sounds like G; B𝄫 sounds like A:
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An accidental lasts the whole bar
Once an accidental appears, it applies to every note on that same line or space until the bar line — in that octave only. The next bar starts fresh. To get the plain note back before the bar ends, the composer writes a natural.
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In bar 1, both Fs are sharp although only the first has the sign. In bar 2 they're natural again. In bar 3, a natural cancels the sharp halfway through.
Courtesy accidentals (or cautionary accidentals) are reminders that aren't strictly needed — for example, a natural in the bar after a sharp, sometimes in brackets: (♮). They don't change anything; they just save you from doubting.
Key signatures
Most songs stay in one key, so the same sharps or flats would appear over and over. Instead, they're written once, right after the clef on every line: the key signature. It means "play these notes sharp (or flat) everywhere, in every octave, unless an accidental says otherwise".
The key of G major has one sharp, F♯ — on the top line, but it applies to every F:
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None of the F♯s has a sign of its own: the key signature already says so. Click one and you'll hear (and see in the tab) the 4th fret of the D string.
D major has two sharps, F♯ and C♯:
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F major has one flat, B♭:
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The order of sharps and flats
Sharps and flats are always added in the same order:
- Sharps: F C G D A E B — Father Charles Goes Down And Ends Battle.
- Flats: B E A D G C F — the same list backwards (Battle Ends And Down Goes Charles' Father).
So a key with three sharps always has F♯, C♯ and G♯; a key with two flats always has B♭ and E♭.
Naming the key from its signature
- Sharps: the last sharp is the 7th note of the major key — go up a half step. Three sharps (F♯ C♯ G♯) → A major.
- Flats: the second-to-last flat is the key. Three flats (B♭ E♭ A♭) → E♭ major. One flat is the exception to memorize: F major.
- Nothing: C major.
| Signature | Major key | Relative minor |
|---|---|---|
| none | C | A minor |
| 1♯ | G | E minor |
| 2♯ | D | B minor |
| 3♯ | A | F♯ minor |
| 4♯ | E | C♯ minor |
| 5♯ | B | G♯ minor |
| 6♯ | F♯ | D♯ minor |
| 7♯ | C♯ | A♯ minor |
| 1♭ | F | D minor |
| 2♭ | B♭ | G minor |
| 3♭ | E♭ | C minor |
| 4♭ | A♭ | F minor |
| 5♭ | D♭ | B♭ minor |
| 6♭ | G♭ | E♭ minor |
| 7♭ | C♭ | A♭ minor |
The circle of fifths shows the same thing as a picture.
Major or minor?
Every major key shares its signature with a relative minor, three half steps lower: G major and E minor both have one sharp. To tell which one a piece is in, look at the first and last notes and chords, and at extra accidentals: minor keys often raise their 7th note (D♯ in E minor), which shows up as an accidental.
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The D♯ comes from the B7 chord — it's the leading tone of the harmonic minor.
Key changes
A piece can change key in the middle (a modulation). The new key signature appears after a double bar line; if sharps or flats are removed, naturals show which ones are cancelled.
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Practice
Before playing anything, say the key signature out loud — "one sharp, F♯: G major or E minor" — then scan the music for extra accidentals and mark them.