Key & Scale Finder: Detect a Song’s Musical Key

Type or tap the notes in your melody
Use letters like C, C#, Db, F, G. Separate them with spaces or commas. The tool scores every major and minor key against your note set.
Tip: the more notes you feed in, the more reliable the result. Five to eight notes spanning a phrase beats three isolated chords. Accidentals are accepted as sharps or flats (Db equals C#).

Detect by Ear with Your Microphone

Sing or play a note into your mic and it is added to the sequence. Microphone access starts only after you press the button.

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Pitch detection works best with a single clear tone (voice whistle, a sustained note). Noisey rooms produce unstable readings, so this is an aid, not a replacement for typing the notes you already know.
Key & Scale Finder

Work out the key of any melody from the notes you know

Type the notes in your melody and this free key finder instantly ranks the major and minor keys that best fit, with optional microphone pitch detection for singers and players.

What Is a Key and Scale Finder?

A key and scale finder works out the home note and mode of a piece of music from the notes you give it. Every song in common practice lives in one of twelve major or twelve minor keys, and each key contains a fixed set of seven notes drawn from the twelve-tone chromatic scale. If you know which notes appear in a melody or chord progression, you can compare that set against every possible scale and the key with the most overlapping notes is almost always the answer.

This tool does exactly that comparison in the browser. Enter the notes you can hear or play, and it scores all twenty-four diatonic keys, plus harmonic and melodic minor variants, against your note set. It returns the best match as a headline and the next five candidates underneath, so you can judge how confident the result is rather than trusting a single number.

How It Works

1
Enter your notesType note names separated by spaces or commas (C, C#, Db, F, G are accepted), or tap the quick-pick pads to build the set.
2
Score every keyPress Detect Key. The tool maps each note to a pitch class from 0 to 11, then checks how many of your notes belong to each root’s major, natural minor, harmonic minor, and melodic minor scale.
3
Read the rankingThe key that contains the largest share of your notes wins. It appears as a headline, with the next five candidates shown underneath so you can judge the confidence.
4
Optional mic inputThe microphone mode listens to one sustained tone at a time and adds the detected note. Because pitch tracking is noisy, it is an aid when you are unsure, not a substitute for typing what you know.

Tips for Best Results

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Feed in five to eight notesTwo notes fit almost every key; seven notes usually lock it down. Grab notes from a full phrase, not just the tonic chord.
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Include the accidentalsThe raised sixth or seventh degree that separates harmonic minor from natural minor is often what decides between two close candidates.
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Trust the gap between placesIf the top two scores are within a few percent, the song may be modal or borrowed-chord territory; treat the result as a strong hint, not fact.
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Use flats and sharps interchangeablyDb and C# are the same pitch class here, so spell the way that feels natural.

Who It’s For

SongwritersCheck whether a sketched melody actually lives in the key you think it does.
Cover musiciansTranspose a song into a vocal range you can sing.
StudentsEar-training practice: guess the key first, then test yourself against the tool.
ProducersFind the original key of an old record before chopping a break.

It is maintained by Mel as part of the MuseLift toolset, alongside the chord transposer and the tap tempo meter. Browse the full collection in the songwriting tools hub.

FAQ

Can it tell major from minor?
Yes. It scores major, natural minor, harmonic minor, and melodic minor for every root and ranks them separately, so a song in A minor is not confused with C major just because the raw notes overlap.
What if my notes fit two keys equally?
That is normal. Relative major and minor share all seven notes, so a clean diatonic phrase will often tie. Look at the harmony and which note feels like rest.
Does the microphone listen to me all the time?
No. Audio only turns on after you press Start Microphone and stops when you press again or leave the page. Nothing is recorded or uploaded.
Why do I see jazz modes not in the list?
This finder focuses on the major and minor keys most songwriters actually use. Modes like Dorian or Mixolydian are close cousins you can infer once the diatonic key is known.
Is it really free?
Yes. No account, no upload, no limits. The analysis runs entirely on your device.