How to Read a Key Signature

Key signatures are used in written music to indicate which notes in a piece must be raised or lowered a half step. They are also used to determine in what key the piece of music is written. Key signatures are made up of all sharps or all flats, always in the same order. Read on to learn how to read a key signature.

Difficulty: Moderately Easy

Instructions

Sharp Key Signatures

1. Look in the first measure of your piece, just to the right of the clef symbol. Key signatures are always notated between the clef symbol and the time signature.

2. Find the last sharp in the key signature and go up one half step. This note is the major key for that key signature.

3. Move down three half steps from the root of the key signature's major scale to find the relative minor for that key signature. For example, the relative minor of G major is E minor.

4. Play the piece, remembering to raise each note in your key signature one half step unless a new key signature is indicated.

Flat Key Signatures

5. Find the key signature in the first measure of your piece of music. It is located between the clef symbol and the time signature.

6. Look at the second to last flat in the key signature. This flat is the major key of your piece. F major doesn't follow this rule because it only contains one flat. This key signature must simply be memorized.

7. Go down three half steps from the root of the major key to find your key signature's relative minor key. For example, the relative minor of B major is G minor.

8. Remember to lower the notes of the key signature by one half step throughout the entire piece unless a new key signature is notated.

Tips & Warnings

• If there are no sharps or flats in the key signature, this indicates that the piece is either written in C major or its relative minor, A minor.
• To remember the order of sharps, "F, C, G, D, A, E, B," memorize the following phrase: Fat Cats Go Down Alleys Eating Bugs.