A key signature appears at the start of every staff line and tells you which notes are consistently sharp or flat throughout a piece — eliminating the need to mark every single note. There are 30 key signatures in total, spanning 7 sharps to 7 flats.
Click any key to see its signature rendered on a grand staff, with every sharp or flat in its correct notated position.
Grand Staff
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Scale Notes
Relative Minor
A minorQUICK TIP
No sharps or flats — all white keys. The natural starting point for learning key signatures.
Piano — C major
A key signature sits right after the clef at the start of every staff line. It places sharp (♯) or flat (♭) symbols on specific lines and spaces to declare: every time you encounter this note, raise or lower it by a half step — for the entire piece.
Without a key signature, music in G major would need an F♯ written before every F note. The key signature writes it once and applies it everywhere — saving space and making the music far easier to sight-read.
The position of each sharp or flat on the staff is standardized and fixed. F♯ always appears on the top line of treble clef; B♭ always sits on the middle line. This consistency makes key signatures recognizable at a glance.
C major (no accidentals) vs G major (1 sharp — F♯)
The F♯ in G major's key signature means every F in the piece is automatically raised — no per-note marking needed.
Flats are always added in this order: B♭ E♭ A♭ D♭ G♭ C♭ F♭. Mnemonic: "Battle Ends And Down Goes Charles's Father." (Reverse of sharps.)
| Key | Flats | Added Flat | Rel. Minor | Notes |
|---|---|---|---|---|
| F | 1♭ | B♭ | Dm | F G A B♭ C D E |
| B♭ | 2♭ | E♭ | Gm | B♭ C D E♭ F G A |
| E♭ | 3♭ | A♭ | Cm | E♭ F G A♭ B♭ C D |
| A♭ | 4♭ | D♭ | Fm | A♭ B♭ C D♭ E♭ F G |
| D♭ | 5♭ | G♭ | B♭m | D♭ E♭ F G♭ A♭ B♭ C |
| G♭ | 6♭ | C♭ | E♭m | G♭ A♭ B♭ C♭ D♭ E♭ F |
| C♭ | 7♭ | F♭ | A♭m | C♭ D♭ E♭ F♭ G♭ A♭ B♭ |
Click any row to jump to that key in the explorer.
The Circle of Fifths arranges all 12 major keys in a ring where each key is a perfect fifth above its clockwise neighbor. Moving clockwise adds one sharp; moving counterclockwise adds one flat.
This explains the predictable pattern: C (0) → G (1♯) → D (2♯) → A (3♯) →… Adjacent keys on the circle always differ by exactly one accidental, which is why the entire key signature system is learnable in a single diagram.
Explore the Circle of Fifths →Find the last sharp (rightmost on the staff). Go one half step higher — that's the key.
Example: Last sharp = D♯ → half step up = E → E major (4♯)
Look at the second-to-last flat — its name is the key. (Exception: one flat = F major.)
Example: Flats: B♭ E♭ A♭ D♭ → second-to-last = A♭ → A♭ major
An empty key signature means C major or A minor — all white keys, no alterations.
Identify the key from the staff notation.
What key is this?
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Every major key shares its key signature with a relative minor. They use the exact same set of notes — the minor scale simply starts on the 6th degree of the major.
C major and A minor both have zero accidentals. G major and E minor both have one sharp (F♯). Use the Relative Minor toggle in the explorer above to hear and see this relationship.
| Major Key | Accidentals | Relative Minor | Minor Tonic |
|---|---|---|---|
| C | None | A minor | A |
| G | 1♯ | E minor | E |
| D | 2♯ | B minor | B |
| A | 3♯ | F♯ minor | F♯ |
| E | 4♯ | C♯ minor | C♯ |
| B | 5♯ | G♯ minor | G♯ |
| F♯ | 6♯ | D♯ minor | D♯ |
| C♯ | 7♯ | A♯ minor | A♯ |
| F | 1♭ | D minor | D |
| B♭ | 2♭ | G minor | G |
| E♭ | 3♭ | C minor | C |
| A♭ | 4♭ | F minor | F |
| D♭ | 5♭ | B♭ minor | B♭ |
| G♭ | 6♭ | E♭ minor | E♭ |
| C♭ | 7♭ | A♭ minor | A♭ |