Key Signatures
Learn how key signatures organize musical scales and establish tonality.
Understanding Key Signatures
A key signature appears at the beginning of a piece of music and shows which notes should be consistently played as sharps or flats throughout the piece. Key signatures help establish the tonal center and make sheet music easier to read by reducing the number of accidentals needed.
Common Key Signatures
Some key signatures are more commonly used than others. Here are some of the most frequently encountered key signatures:
C major
Key Signature: No sharps or flats
Notes: C D E F G A B
Relative Minor: A minor
Often used for beginning pieces and simple melodies
G major
Key Signature: 1 sharp (F♯)
Notes: G A B C D E F♯
Relative Minor: E minor
Common in folk and country music
D major
Key Signature: 2 sharps (F♯, C♯)
Notes: D E F♯ G A B C♯
Relative Minor: B minor
Popular in guitar-based music
F major
Key Signature: 1 flat (B♭)
Notes: F G A B♭ C D E
Relative Minor: D minor
Common in concert band music
The Circle of Fifths
The Circle of Fifths is a powerful tool for understanding the relationships between keys and their signatures. Moving clockwise adds sharps, while moving counterclockwise adds flats.
C / Am
Accidentals: 0
G / Em
Accidentals: 1♯
D / Bm
Accidentals: 2♯
A / F♯m
Accidentals: 3♯
E / C♯m
Accidentals: 4♯
F / Dm
Accidentals: 1♭
B♭ / Gm
Accidentals: 2♭
E♭ / Cm
Accidentals: 3♭
Order of Sharps and Flats
Order of Sharps
F♯ C♯ G♯ D♯ A♯ E♯ B♯
Mnemonic: "Father Charles Goes Down And Ends Battle"
Order of Flats
B♭ E♭ A♭ D♭ G♭ C♭ F♭
Mnemonic: "Battle Ends And Down Goes Charles Father"
Key Signature Rules
- Major Keys: The last sharp is the leading tone (7th scale degree)
- Flat Keys: The second-to-last flat is the key name
- Relative Minor: Down a minor third from the major key
- Parallel Keys: Same tonic note but different mode (e.g., C major/C minor)
Practice Exercises
Exercise 1: Key Signature Identification
Practice identifying key signatures by counting sharps or flats and using the Circle of Fifths.
Exercise 2: Finding Relative Keys
For each major key, find its relative minor and vice versa.
Exercise 3: Writing Key Signatures
Practice writing key signatures in the correct order on the staff.
Key Takeaways
- Key signatures indicate which notes are consistently sharp or flat throughout a piece
- The Circle of Fifths shows relationships between keys and their signatures
- Sharps and flats follow a specific order when added to key signatures
- Every major key has a relative minor that shares the same key signature
- Understanding key signatures is essential for reading and writing music