To use the circle of fifths, find your key on the circle, read its key signature from the number of sharps or flats, and look at the keys next to it for closely related keys to modulate to. The keys next to C major are G major, F major, A minor, E minor and D minor.
How do you use the circle of fifths?
The circle of fifths is a tool, not a decoration, and it answers four practical questions: what is the key signature of this key, what are the closely related keys, what is the relative minor, and where can I modulate to. Find your key on the circle, read the number of sharps or flats next to it, and look at the keys beside it: the keys next to yours are the closely related keys, the key inside yours is the relative minor, and the keys further away are the distant keys that sound dramatic when you move to them. The most common use is finding closely related keys for modulation. If you are writing in C major and you want to change key, the easiest moves are to G major or F major, the keys one step away in either direction, because they share six of their seven notes with C major and the change sounds smooth. The next easiest moves are to A minor, E minor and D minor, the relative minor and the minors of the neighbouring majors, which also share most of their notes with C major. Moving further around the circle, to D major or Bb major, sounds more dramatic, because fewer notes are shared, and that drama is sometimes exactly what a song needs.
How the circle helps with chords and transposition
The circle also tells you which chords belong to a key, because the chords of a key are built from its scale, and the scale is built from its key signature. In C major the chords are C, Dm, Em, F, G, Am and Bdim, and the circle shows that G major shares six of those notes, so the chords of G major, G, Am, Bm, C, D, Em and F#dim, overlap with the chords of C major in five places. That overlap is why a song can move between C major and G major without changing many notes, and why the I–V movement, C to G, is the most common chord movement in music: the two keys sit next to each other on the circle. For transposition, the circle tells you how far to move and what the new key signature will be. To transpose a song from C major to D major, move two steps clockwise on the circle, from no sharps to two sharps, and move every note up by a whole tone. To transpose from G major to C major, move one step anticlockwise, from one sharp to no sharps, and move every note down by a perfect 5th. The chord transposer does the calculation for you, and the key finder finds the key of a set of chords using the circle.
Worked example — modulating from C major to G major. The two keys sit next to each other on the circle, so they share six notes: C, D, E, G, A and B are in both scales, and only F changes, from F natural in C major to F# in G major. To modulate, play a pivot chord that belongs to both keys, such as C major or Am, and then introduce the F# in the next chord, such as D major, the V chord of G major. The listener hears the F# as a new colour, and the music has moved to G major without a jolt. The I–V–vi–IV progression in G major shows the chords of the new key, and the key of G major lists them.
How to practise using the circle of fifths
Practise the circle by using it to answer real questions about real music, not by staring at the diagram, so the skill becomes practical.
- Pick a song in C major and use the circle to find its closely related keys, then try modulating to G major using a pivot chord.
- Take a chord progression in G major and transpose it to D major, moving two steps clockwise on the circle and adding one sharp.
- Find the relative minor of the key of D major using the circle, and check that it shares the same key signature.
- Write out the chords of the key of F major and the key of C major, and count how many chords they share.
- Use the circle of fifths tool to find the key signature of a key you have never played in, and then play its scale.
Common mistakes
- Modulating to a distant key without preparation — Moving two or more steps around the circle sounds dramatic, which is fine if that is what you want, but it will sound like a mistake if the listener is not prepared. Use a pivot chord or a secondary dominant to prepare a distant modulation.
- Forgetting that the relative minor shares the key signature — The relative minor sits inside the circle at the same position as its major partner, so it has the same key signature. If your relative minor has a different number of sharps or flats, you have the wrong minor.
- Using the circle only for key signatures — The circle also shows closely related keys, relative minors, chord relationships and transposition distances. If you only use it for key signatures, you are using a tenth of what it can do.
Quick reference
This table lists the closely related keys of four common keys, with the number of notes they share, so you can see how the circle measures musical distance. The keys next to yours on the circle share six of their seven notes, which is why modulation to them sounds smooth, while keys further away share fewer notes and sound more dramatic.
| Your key | Closely related keys | Shared notes |
|---|---|---|
| C major | G major, F major, A minor, E minor, D minor | 6 of 7 notes |
| G major | C major, D major, E minor, B minor, A minor | 6 of 7 notes |
| D major | G major, A major, B minor, F# minor, E minor | 6 of 7 notes |
| F major | C major, Bb major, D minor, A minor, G minor | 6 of 7 notes |
Use the table as a modulation guide: when you want to change key smoothly, choose one of the closely related keys in the second column, and use a pivot chord that belongs to both keys to make the move. When you want drama, choose a key further around the circle, and prepare the listener with a secondary dominant.
Frequently asked questions
How do I use the circle of fifths to find a key signature?
Find the key on the circle and count the steps from C major: each step clockwise adds one sharp, and each step anticlockwise adds one flat. A major is three steps clockwise, so it has three sharps, F#, C# and G#.
What are closely related keys?
The keys that sit next to a key on the circle of fifths, plus the relative minor. The closely related keys of C major are G major, F major, A minor, E minor and D minor, and they share most of their notes with C major.
How do I use the circle of fifths to transpose?
Count the steps between the old key and the new key on the circle, and move every note by the same interval. Moving one step clockwise means moving up a perfect 5th and adding one sharp; moving one step anticlockwise means moving down a perfect 5th and adding one flat.
Can the circle of fifths help me write chord progressions?
Yes. The chords of a key are built from its scale, and the circle shows which keys share notes, so it shows which chords fit together. The I, IV and V chords of a key are the tonic and the keys one step away in either direction, which is why they sound so natural together.
What is the relative minor on the circle of fifths?
The minor key that sits inside the circle at the same position as its major partner, sharing the same key signature. The relative minor of C major is A minor, the relative minor of G major is E minor, and the relative minor is always a minor 3rd below the major root.