Key Signatures

A key signature is the group of sharps or flats written at the start of every staff, right after the clef. It tells you which notes are sharp or flat all the way through the music, and which key the music is in: one major key, or its relative minor.

By Dan Vrancic, music theory teacher · Reviewed October 2026

Key signature chart

There are 15 major key signatures: C major with none, seven with sharps and seven with flats. Every signature is shared by a major key and its relative minor, so the same 15 signatures cover 30 keys.

Sharp keys

  • C major

    A minor · no sharps or flats

  • G major

    E minor · 1 sharp

  • D major

    B minor · 2 sharps

  • A major

    F♯ minor · 3 sharps

  • E major

    C♯ minor · 4 sharps

  • B major

    G♯ minor · 5 sharps

  • F♯ major

    D♯ minor · 6 sharps

  • C♯ major

    A♯ minor · 7 sharps

Flat keys

  • F major

    D minor · 1 flat

  • B♭ major

    G minor · 2 flats

  • E♭ major

    C minor · 3 flats

  • A♭ major

    F minor · 4 flats

  • D♭ major

    B♭ minor · 5 flats

  • G♭ major

    E♭ minor · 6 flats

  • C♭ major

    A♭ minor · 7 flats

SharpsMajor keyRelative minor
0C majorA minor
1G majorE minor
2D majorB minor
3A majorF♯ minor
4E majorC♯ minor
5B majorG♯ minor
6F♯ majorD♯ minor
7C♯ majorA♯ minor
FlatsMajor keyRelative minor
1F majorD minor
2B♭ majorG minor
3E♭ majorC minor
4A♭ majorF minor
5D♭ majorB♭ minor
6G♭ majorE♭ minor
7C♭ majorA♭ minor

Three pairs of keys sound the same but are spelled differently: B and C♭, F♯ and G♭, C♯ and D♭. These are enharmonic keys.

The order of sharps and flats

Sharps are always added in one fixed order, and flats in the reverse of that order. A signature with three sharps always has the first three sharps, never any others.

Order of sharps

  1. FFather
  2. CCharles
  3. GGoes
  4. DDown
  5. AAnd
  6. EEnds
  7. BBattles

Order of flats

  1. BBattles
  2. EEnd
  3. AAnd
  4. DDown
  5. GGoes
  6. CCharles’
  7. FFather

How to identify a key signature

You do not need to memorize the chart. Two short rules name the major key of almost any signature.

  1. Sharps: last sharp, up a semitone

    Find the last sharp in the signature and go up to the next letter name. Three sharps end on G♯; the next letter up is A, so the key is A major.

  2. Flats: the second-to-last flat

    The second-to-last flat is the name of the key, flat included. Four flats end B♭, E♭, A♭, D♭; the second-to-last is A♭, so the key is A♭ major.

  3. Learn two by heart

    No sharps or flats is C major. One flat has no second-to-last flat, so learn it: F major.

Sharps

A major: 3 sharps

The last sharp is G♯. One letter up is A.

Flats

A♭ major: 4 flats

The second-to-last flat is A♭.

To go the other way, from a key to its signature, use the same rules backwards. How many sharps in E major? E has to be one letter above the last sharp, so the last sharp is D♯: F♯, C♯, G♯, D♯. That is four sharps.

Try it: name the key

Question 1 of 6

Which major key has this signature?

Major or minor?

A signature on its own cannot tell you whether a piece is in the major key or its relative minor. Look at the music instead:

  • The raised 7th. Minor keys usually raise their 7th note with an accidental. A piece with one sharp and frequent D♯s is probably in E minor, not G major.
  • First and last notes. Melodies and pieces tend to begin and end on the tonic, the note the key is named after.

The relative minor's tonic is always three semitones (a minor third) below the major key's tonic: G major and E minor share one sharp.

See it step by step

The interactive explainer from Lesson 9, with sound. Step through it at your own pace.

See it take shape · Interactive story

One sharp at a time

Line the major keys up by how many sharps or flats they need, and the sharps and flats fall into a fixed order. Then collect them after the clef, one at a time, each on its own line or space.

Step 1 of 11
C0G1♯
G major needs one accidental: F♯. C major needs none. Tap a key below to change it.

Keys

A key is named after its scale

A piece that uses the G major scale is in G major: the key takes its name from the scale’s starting note. Every major scale follows the same T–T–S–T–T–T–S pattern, but not every key needs the same accidentals.

Same pattern, different accidentals: G major needs F♯.

Use the arrow keys while a story control is focused.

Read the story as text

  1. A key is named after its scale

    A piece that uses the G major scale is in G major: the key takes its name from the scale’s starting note. Every major scale follows the same T–T–S–T–T–T–S pattern, but not every key needs the same accidentals.

  2. Line up the sharp keys

    Sort the major scales that use sharps from fewest to most: G has one, D has two, and so on up to C♯ with seven. Tap a key to see its scale.

  3. Each key is a 5th above the last

    Each new key sits a perfect 5th above the last. Count five letter names up from C (C, D, E, F, G) and you reach the next key, G.

  4. Keep going and you come back round

    Keep stepping up a 5th and you eventually return to where you started. That is why musicians draw the keys as a circle of fifths.

  5. The sharps always come in the same order

    Each key keeps the sharps of the one before and adds one more, so two sharps are always F♯ and C♯, and three add G♯. Read the new sharps along the line: F C G D A E B.

  6. The flats are the same order, backwards

    Flat keys follow the circle backwards, from F to C♭, adding one flat each time. The flats appear in the exact reverse order of the sharps: B E A D G C F.

  7. Write them once, after the clef

    Instead of writing an accidental in front of every note, collect the scale’s sharps or flats and write them once after the clef, at the start of every line. That group is the key signature: it tells you every sharp or flat to play.

  8. Each sharp has its own place

    The sharps are written in order, each on its own line or space. In the treble clef F♯ starts on the top line and the rest zig-zag down and up: C♯, G♯, D♯, A♯, E♯, B♯.

  9. Bass clef: the same shape, one space lower

    In the bass clef the sharps keep the same order and the same zig-zag. The whole pattern moves down one space: F♯ goes from the top line to the fourth line.

  10. The flats have their places too

    The flats start with B♭ on the middle line of the treble staff, then go up to E♭ and down to A♭, swinging back and forth. In the bass clef the pattern also sits one space lower.

  11. Write the key signature

    Write each key signature one sign at a time, in order. Move the marker to the line or space where the next sharp or flat belongs, then write it.

Practice on paper

Free printable worksheets on this topic, each with an answer key.

Key signature worksheets with answer keys

Questions about key signatures

How many key signatures are there?
There are 15 major key signatures: C major with no sharps or flats, seven with sharps (G, D, A, E, B, F♯, C♯) and seven with flats (F, B♭, E♭, A♭, D♭, G♭, C♭). Each one is shared by a relative minor key, so 15 signatures cover 30 keys.
Which key has no sharps or flats?
C major, and its relative minor, A minor.
What is the order of sharps?
F, C, G, D, A, E, B. A common way to remember it is “Father Charles Goes Down And Ends Battles.” A key signature with three sharps always has the first three: F♯, C♯ and G♯.
What is the order of flats?
B, E, A, D, G, C, F: the order of sharps backwards. Read the same sentence backwards: “Battles End And Down Goes Charles’ Father.”
How do you find the key of a signature with sharps?
Take the last sharp and go up one letter name, a semitone higher. Three sharps end on G♯, so the key is A major.
How do you find the key of a signature with flats?
The second-to-last flat is the name of the key. Four flats are B♭, E♭, A♭, D♭; the second-to-last is A♭, so the key is A♭ major. One flat is the exception to learn by heart: F major.
How can you tell if a piece is in a major or a minor key?
The signature alone cannot tell you, because a major key and its relative minor share one. Look at the music: minor keys usually raise their 7th note with an accidental (G♯ in A minor), and pieces tend to begin and end on the tonic chord.

Learn it properly

The course teaches key signatures in 2 video lessons with practice questions, graded quizzes and printable sheets.

See plans