How to find a song's key, then change it to fit your voice

Why the key matters

A song's key is its home note and whether it's major or minor: G major, or E minor. The home note, the tonic, is where the music feels finished; the melody and the chords are built around it. When you change the key, every note of the song moves by the same distance, so the tune and the chords keep their shape and only get higher or lower.

For a singer, the key decides where the melody's highest and lowest notes land against your range. For a player, it decides which chords and shapes you'll use. Knowing it also helps you jam along, write a harmony, or pick songs that flow into each other in a set.

Find the key by ear: the tonic test

Your ear can do this with a little practice, though some songs fight it: songs that start on a minor chord but are really major, songs that change key for the last chorus, and songs that hover without ever landing. If your ear and a tool disagree, the relative key (further down) is the usual reason. The routine:

1. 1Play the song and stop at the end of the chorus or the very end, where it sounds finished.
2. 2Hum the note that feels like home, the one the song wants to rest on. Hold it while the music plays: if it sounds settled under every chord at the end, that's likely the tonic.
3. 3Find that note on a piano or keyboard app by sliding along until it matches your hum.
4. 4Decide major or minor: from the tonic, sing up three steps of the scale. A bright, happy sound is major; a darker, sadder one is minor.
5. 5Check with the chords if you play: the first and last chords of a song are often the tonic chord, and most of the chords should fit the key's seven notes.

Check your ear against a tool

A finder is quickest when you treat it as a second opinion. Run the song through it, then do the tonic test above with its answer in mind: hum the key note it names over the last chord. If it sits still, you're done; if it pulls somewhere else, try the other key it offers.

Two kinds of disagreement are common, and both are easy to settle. The tempo can come back at half or double what you'd count, because a beat can be felt at two speeds; pick whichever matches your foot. The key can come back as its relative, the major or minor built from the same notes, and the next section shows how to tell those apart. A song that changes key for its last chorus has no single right answer, so read the verse and the final chorus separately by ear.

When the finder isn't sure, splitting the song first usually helps, because the voice and drums no longer cloud the chords. Its own page explains how it reads tempo and key and what each kind of answer means.

How the finder works, and what its answers mean

Relative major and minor, explained

Every major key shares its seven notes with one minor key, its relative minor, whose tonic is three semitones lower. C major and A minor, for instance, are both played on the white keys alone; G major pairs with E minor the same way, and F major with D minor. Same notes, different home.

That makes them easy to mix up, by ear and by software: the notes alone can't say which one is home. Your ear can: listen to the final chord and the bass note under it. If the finder shows a key with the other one beside it, that's usually this pair, and your ear settles it. For changing the key it doesn't matter much: moving a song down three semitones moves it down three semitones, whichever name it has.

Move the song into your range

Line up two numbers: the melody's top note and your own top note. The gap between them, in semitones, is your first guess at the move: three over means three down. Then look at the other end. If the melody's lowest note now falls below your range, the song is wider than your comfortable range and something has to give; losing a little of the bottom usually costs less than straining at the top. On the pitch changer each step is one semitone, the full reach is 12 each way, the tempo is untouched, and you can audition every step before saving.

If you know your voice type but not your exact range, the typical ranges give a starting point. Here's how far a song written for one type moves to suit another:

Find your own range with the vocal range test

Guitarists: the capo does the same thing

A capo raises every string by one semitone per fret, so you play the chord shapes you know and the song comes out higher. It's the same arithmetic as the pitch changer, in your hands: if the singer needs the song two semitones up, a capo on fret 2 does it. If they need it lower, a capo can't help; tune down, or move the recording with the pitch changer and play along with that.

A worked example

Say a song is in E major and its melody runs from B3–E5, and your comfortable range is C3–A4. The top of the melody is 7 semitones above your highest note, so move the song down 7 semitones. The melody now runs E3–A4, inside your range at both ends, and the song is in A major.

Why not just sing it an octave down? That would put the melody at B2–E4, with the bottom below your lowest note. Moving by 7 semitones lands it where you can sing every note.

A guitarist playing along in the original E shapes can follow the new key with a capo on fret 5: E shapes there sound in A. On the pitch changer, it's 7 semitones down, then save.

Slow it down to learn it

Once the key is right, the fast passages are next. The finder's tempo gives you the BPM to set a metronome to. In the practice player you can slow the song to as little as 50% while it keeps your new key, loop the hard bars with A and B, and let it speed up a little on each pass. Practice opens any song up to 10 minutes long directly; speed and key don't need a split.

Practise it slower in the practice player