Circle of Fifths: Interactive Music Theory Tool & Guide
Master the Circle of Fifths with our interactive tool. Learn key signatures, chord progressions, relative minors, and how to use the circle for songwriting.
The Circle of Fifths is the "periodic table" of music. It organizes the 12 chromatic pitches into a sequence of perfect fifths, revealing the hidden relationships between keys, chords, and scales.
Circle of Fifths
Interactive music theory tool - click keys to hear chords
Moving clockwise adds sharps • Moving counter-clockwise adds flats
How to Read the Circle
The diagram might look complex, but it follows a simple, logical pattern.
1. The Clockwise Motion (Fifths)
Moving clockwise, every step is a Perfect Fifth (7 semitones) higher.
- C → G → D → A → E...
- With each step, you add one Sharp (#) to the key signature.
2. The Counter-Clockwise Motion (Fourths)
Moving counter-clockwise, every step is a Perfect Fourth (5 semitones) higher (or a Fifth lower).
- C → F → Bb → Eb → Ab...
- With each step, you add one Flat (b) to the key signature.
3. Inner Ring (Relative Minors)
The inner circle shows the Relative Minor for each Major key.
- C Major and A Minor share the exact same notes (no sharps/flats).
- This is crucial for modulation—moving between relative keys is the smoothest way to change the mood of a song without clashing.
Key Signatures Reference
| Key (Major) | Key (Minor) | Sharps / Flats | Notes Affected |
|---|---|---|---|
| C | Am | 0 | None |
| G | Em | 1 Sharp | F# |
| D | Bm | 2 Sharps | F#, C# |
| A | F#m | 3 Sharps | F#, C#, G# |
| E | C#m | 4 Sharps | F#, C#, G#, D# |
| B | G#m | 5 Sharps | F#, C#, G#, D#, A# |
| F# | D#m | 6 Sharps | All except B (E# is F) |
| F | Dm | 1 Flat | Bb |
| Bb | Gm | 2 Flats | Bb, Eb |
| Eb | Cm | 3 Flats | Bb, Eb, Ab |
| Ab | Fm | 4 Flats | Bb, Eb, Ab, Db |
| Db | Bbm | 5 Flats | Bb, Eb, Ab, Db, Gb |
Using the Circle for Songwriting
The Circle of Fifths is the ultimate cheat sheet for writing chord progressions.
Finding "In-Key" Chords
Pick any Major key on the circle (e.g., C). The 5 chords surrounding it are the "diatonic" chords that will always sound good together.
For C Major:
- The Root (I): C Major
- Clockwise Neighbor (V): G Major (Dominant)
- Counter-Clockwise (IV): F Major (Subdominant)
- Inner Ring (vi): A Minor
- Inner Clockwise (iii): E Minor
- Inner Counter (ii): D Minor
These 6 chords make up 99% of pop songs in the key of C.
Modulation (Changing Keys)
To change keys smoothly, move to a neighboring slice on the circle.
- C → G: Very smooth (adds 1 sharp).
- C → F: Very smooth (adds 1 flat).
- C → D: A bit brighter (adds 2 sharps), often used for an "energy lift."
The Physics: Why 3:2?
A Perfect Fifth represents a frequency ratio of 3:2. This is the most stable and consonant interval after the octave (2:1).
- If A = 220 Hz
- The Fifth (E) = 330 Hz (220 × 1.5)
This mathematical purity is why the Fifth is the structural backbone of Western harmony and why "Power Chords" (Root + Fifth) sound so strong.
FAQ
Why doesn't the circle close perfectly?
In pure physics (Pythagorean tuning), stacking 12 perfect fifths results in a pitch slightly higher than 7 octaves. This tiny discrepancy is called the Pythagorean Comma. Modern instruments use "Equal Temperament" tuning, which slightly flattens the fifths so the circle closes perfectly.
How do I memorize it?
Use a mnemonic:
- Sharps (Clockwise): Father Charles Goes Down And Ends Battle.
- Flats (Counter-Clockwise): Battle Ends And Down Goes Charles' Father.
What is the tritone?
The key directly opposite on the circle (e.g., C and F#) is the Tritone (augmented 4th / diminished 5th). This is the most dissonant interval and is often used in jazz for "Tritone Substitution."
Related Tools:
- Interval Training - Learn to hear these distances
- Piano Frequencies - See the Hz behind the keys
- Instrument Tuner - Tune to perfect fifths