Same seven notes, different front door. That's the entire personality difference between a major key and its relative minor — and once you know the three-semitone trick, you never need to squint at a circle-of-fifths poster again. Want the full walkthrough, including the "Hurt" example and the major/minor chord comparison? Read The Relative Key → first; this is the pocket version for when you just need the answer, fast.
The Three-Semitone Rule
Here's the whole trick: to find a major key's relative minor, count down three semitones — a minor third — from the major tonic. To go the other way, count up three semitones from the minor tonic to land on its relative major. C major down three semitones is A, so A minor is its relative minor; A minor up three semitones is C, so C major is its relative major. That's the entire method — no staff paper required.
A Starter Chart
Six pairs to get you going — the same pattern repeats around all twelve keys:
- C major / A minor — no sharps or flats.
- G major / E minor — one sharp.
- D major / B minor — two sharps.
- A major / F♯ minor — three sharps.
- E major / C♯ minor — four sharps.
- F major / D minor — one flat.
Why the Same Notes Sound Like Two Different Songs
A major key and its relative minor share every note and the exact same key signature — they're not two unrelated scales, they're the same seven notes with a different note declared "home." That's why the three-semitone count only ever narrows things to the right pair of tonics: the key signature is identical on both sides, only the tonic — and the mood — changes.
On the Fretboard
This is handy for improvising, too: over a progression that's clearly sitting in a major key, the relative minor pentatonic shape often works well on top of it, since both draw from the same five notes. It's not a rule with zero exceptions — check it against the melody and the chords first — but it's a solid first guess before you go hunting for a "better" scale.
Want the deep dive, with a real song example and the major-vs-minor chord comparison chart? Head to the full relative key guide →, or brush up on the major key and the minor key on their own. And once you've narrowed a song down to its relative pair, the next move is nailing the actual key — here's how →.
If this saved you from re-deriving the circle of fifths from scratch, you can toss a coffee my way on Patreon — no pressure, purely for the riffs. Now go impress your bass player.