Ever looked at a piece of sheet music and seen a bunch of sharps or flats clustered at the beginning? That’s the key signature, and it tells you what key the music is in. Think of it as a musical shorthand, saving the composer from writing the same accidentals over and over again.
Knowing your key signatures is vital for any musician. It helps you instantly recognize the key of a song, making sight-reading easier and boosting your understanding of music theory.
In this article, we’ll cover how sharps and flats work in key signatures, the order they appear in, the Circle of Fifths and how it relates to key signatures, and how to tell the difference between major and minor keys.
Understanding sharps and flats
Key signatures use sharps and flats to tell you which notes should be played a half-step higher or lower than their natural pitch.
The role of sharps
A sharp symbol (♯) raises the pitch of a note by a half step. Sharps are added to key signatures in a specific order, with each sharp adding a new raised note to the scale.
Keys that use sharps generally have a brighter sound.
The role of flats
A flat symbol (♭) lowers the pitch of a note by a half step. Like sharps, flats are added to key signatures in a specific order, each adding a new lowered note to the scale.
Keys that use flats tend to have a darker or more mellow sound.
The order of sharps and flats
Key signatures can be tricky. Luckily, there are patterns that can help you learn to identify them more easily.
The order of sharps
When key signatures have sharps, they always appear in the same order: F#, C#, G#, D#, A#, E#, and B#. A handy mnemonic for remembering this order is “Father Charles Goes Down And Ends Battle.”
This order is related to the circle of fifths. Each sharp is added a fifth above the tonic of the previous key. For example:
- G major has one sharp: F#
- D major has two sharps: F# and C#
- A major has three sharps: F#, C#, and G#
The order of flats
Flats also appear in a specific order: Bb, Eb, Ab, Db, Gb, Cb, and Fb. You can remember this order by reversing the sharps mnemonic: “Battle Ends And Down Goes Charles’ Father.”
Like sharps, the order of flats follows the circle of fifths, but in the opposite direction (descending). Each flat is added a fifth below the tonic of the previous key. For example:
- F major has one flat: Bb
- Bb major has two flats: Bb and Eb
- Eb major has three flats: Bb, Eb, and Ab
The circle of fifths
The circle of fifths is a visual diagram that shows how all the keys relate to one another. It’s usually drawn as a circle, with the major keys on the outside and the relative minor keys on the inside.
Starting at the top of the circle with C major (which has no sharps or flats), you can move clockwise to add sharps and counterclockwise to add flats. Each step you take around the circle represents an interval of a perfect fifth.
You’ll also notice that some keys are enharmonic, meaning they sound the same but are written differently. For example, F# major and Gb major are enharmonic equivalents.
The circle of fifths is a handy tool for quickly seeing how many sharps or flats each key has. It also illustrates the concept of closely related keys. Keys that are right next to each other on the circle of fifths share many of the same chords.
If you’re trying to identify a key, the circle of fifths can be a useful reference. For instance, if a piece of music has four sharps, you can look at the circle of fifths and see that it’s in E major.
Identifying major and minor keys
Once you know how to identify the key signature, you can figure out whether a piece of music is in a major or minor key.
Determining the major key
When you’re working with sharps, the last sharp you see is always the leading tone, or seventh, of the major key. To name the key, go up a half step from that last sharp.
For instance, if you see a key signature with one sharp — F# — then you know the music is in the key of G major, because G is a half step above F#.
When you’re working with flats, the second to last flat tells you the name of the major key.
In other words, if you see two flats, Bb and Eb, then the key signature is Bb major because Bb is the second to last flat.
Determining the minor key
Every major key has a relative minor key that’s three half steps below it. To find the minor key, first find the major key, and then count down three half steps.
For example, the key of C major has no sharps or flats, so its relative minor is A minor. The key of G major has one sharp, so its relative minor is E minor.
Closing Thoughts
In this article, we covered the basics of key signatures, including sharps and flats, the order of sharps and flats, the circle of fifths, and how these elements relate to major and minor keys. We examined how to look at a key signature and quickly determine the key of a piece of music.
Mastering key signature identification is an essential skill for any musician. It deepens your understanding of music theory and improves your overall performance abilities, whether you’re a singer, instrumentalist, composer, or conductor.
To continue your musical journey, practice identifying key signatures in different pieces of music. Explore more advanced topics, such as modal interchange and altered chords, to expand your theoretical knowledge and creative possibilities. Happy music-making!