The circle of fifths is a visual layout of all 12 major keys and their relative minor keys. The major keys appear on the outer ring, and their relative minors are placed directly inside. Each position on the circle can represent a key, a chord, or a pitch class.

Key Signatures

Key signatures are arranged around the outside of the circle. Major keys and their relative minor keys share the same accidentals.

For example:

• F major and D minor both have one flat.

• G major and E minor both have one sharp.

C major sits at the top of the circle with no sharps or flats.

• Moving clockwise adds one sharp at each step.

• Moving counterclockwise adds one flat at each step.

This organization makes it easy to determine the number of sharps or flats in any key.

Understanding Key Relationships

Keys that are next to each other on the circle are closely related. This helps identify which scales and chords are likely to work well together.

Writing and Harmonizing

The primary chords of a key (I, IV, and V) are located next to each other on the circle. Because of this, the circle is useful for building chord progressions and understanding harmonic movement.

Transposing

To transpose a progression, keep the same pattern of movement on the circle and shift it to a new starting point.

Example:
C – F – G

Shift the same pattern to start on A:
A – D – E

The relationships remain the same; only the tonal center changes.

Perfect Fifths

Each clockwise step moves up a perfect fifth.
Each counterclockwise step moves down a perfect fifth.

After 12 ascending perfect fifths, you return to the starting key.

Using the Interactive Circle

• Use the Clef button to switch clefs.

• Select Hide key signatures to remove accidentals from view.

• Choose Save as PDF to export a printable version of the currently displayed circle.

• Click any key to view its diatonic chords.

Chords are labeled with Roman numerals:

• Uppercase numerals indicate major chords.

• Lowercase numerals indicate minor chords.

• A small circle (°) indicates a diminished chord.

The table below the circle displays:

• The selected key

• Its relative key

• Its parallel key

• All diatonic chords with their scale degree names

Click any chord in the table to hear it.

The circle of fifths is a practical reference for understanding harmony, organizing key signatures, and navigating chord relationships across all keys.