To find the key of a song, open the Key finder (also at key.aden.space) and drop the audio file, or type the song's name, or paste a Spotify, Apple Music, YouTube, SoundCloud or Deezer link. It shows the key, its Camelot code and the BPM, free, in your browser, with no account. No file and no link? Let it listen to the song through your microphone, or find the key by ear on a piano: the note the song keeps coming home to is the key's root.

What is the key of a song?

A song's key is its home note plus the scale built on it. A song in A minor uses mostly the notes A B C D E F G, and A is where it feels finished. There are 24 keys: a major and a minor key on each of the 12 notes.

Two keys can share every note. C major and A minor both use only the white keys of a piano, and only the home note tells them apart. Keep that in mind, because it is the most common reason two tools give two answers (more in why key finders disagree).

How do I find the key of a song from an audio file?

1. Open the Key finder.
2. Drop the file on the page, or press Upload. An acapella, an instrumental or a whole song all work.
3. Read the key, its Camelot code and the BPM.
4. Look at the waveform. It is coloured by key over time, and when the song changes key, each key is printed on the clip's top strip where it starts.
5. Check it by ear. Turn on Piano or Chords at the top and press the key's chords while the song plays (see below).

The file is read in your browser and stays there. You only need an account to save a track to Aden.

How do I find the key of a song by its name or a link?

You don't need the file. In the field beside Upload, type the song's name ("daft punk one more time") or paste a link from Spotify, Apple Music, YouTube, SoundCloud, Deezer or a smart link. Each result shows its key and BPM as soon as they are read. Enter takes the first result, and a link that finds its song adds it at once.

The Key finder reads the key and BPM from half a minute of the song and keeps nothing of it. The song then sits in the playlist as a lane waiting for its audio. If you have the file, drop it on that lane and it is read in full.

Half a minute is not the whole song. A track that changes key later, or one whose verse and chorus sit in different keys, can read differently in full. When the answer matters, drop the file.

How do I find the key of a song that is playing right now?

Use Listen and pick the microphone, a browser tab or your screen's audio (tab and screen audio work in Chrome, Edge and Aden's desktop app). That covers a record in the room, a song on a speaker or a video playing in another tab.

• A red marker glides round the wheel to the key it hears, and the middle of the wheel shows the key and BPM.
• The first key shows within about two seconds of sound.
• After that it reads the last twelve seconds again every second.
• A key only changes once it holds for two readings, so a passing chord does not move it.

Stop listening when you are done. A microphone also hears the room, so talking or a small speaker can blur the reading. A browser tab is usually the cleaner source.

How do I find the BPM of a song?

The same reading gives you the BPM: drop the file, search the song or listen. To count it yourself, the BPM tapper (tap.aden.space) reads the tempo as you tap along. Detectors and people both land on half or double the tempo at times (70 or 140 for the same hip-hop beat), and both numbers describe the same song. The BPM guide covers that.

How to find the key of a song by ear or on a piano

No tool at hand, or you want to confirm what the tool said? You need a piano, a keyboard app or a guitar, and five minutes. The Key finder's Piano view works too: press a key to hear it, or play it from your computer keyboard.

1. Find home. Play the song and hum the note that feels like the end of a phrase. The last bass note of the chorus is usually it. Try piano keys until one matches. That note is the root.
2. Major or minor. Play the major chord and the minor chord on that root while the song plays. One sits, the other clashes. On A, that is A C# E (A major) against A C E (A minor).
3. Play the scale. Play the notes of the key over the song. In A minor that is A B C D E F G. If one note keeps clashing, you are probably one step away on the wheel: E minor differs from A minor by a single note, F# instead of F.
4. Check the chords. Compare the song's chords with the chords of the key. In A minor they are Am, Bdim, C, Dm, Em, F and G, so a song looping Am, F, C and G fits. Many minor songs swap Em for E major. That is still A minor.

The Key finder lists these chords for you. Turn on Chords for the seven chords of the key under the wheel (i ii° III iv v VI VII in a minor key, I ii iii IV V vi vii° in a major one) and press one to hear it.

Relative major and minor: when two answers are both close

Every major key has a relative minor three semitones below its root, with the same notes and the same Camelot number.

The Am, F, C, G loop above fits C major as well as A minor. To decide, listen to where the chorus resolves. If it lands on C, the song is in C major. If it lands on Am, A minor.

For DJing or a mashup the difference rarely matters. Relative keys share every note and mix perfectly. That is why the Key finder aims for the target's relative key when you pitch a minor song towards a major one. The full code table is in the Camelot wheel guide.

What to do with the key once you have it

• Mix it. Songs with the same Camelot number, or one number apart with the same letter, mix without clashing. Set order lines up a DJ set for you (see the Camelot wheel guide).
• Mash it up. Drop an acapella and an instrumental, and the Key finder says how far to pitch and speed one to fit the other. See how to make a mashup.
• Write over it. Turn on Piano or Guitar to see the scale on two octaves of piano or twelve frets of guitar, with a dot on each note and a larger one on the root.
• Keep it. In a dropped track's … menu, Save as track opens New track in Aden with the file, its title, BPM and key filled in.

In ChatGPT or Claude, add Key finder by Aden (mcp.aden.space/key-finder) and ask the same questions, such as "E minor" or "B major to C minor".

FAQ

Is the Key finder free?

Yes. It needs no account, and files you drop stay in your browser. You only sign up to save a track or a mashup to Aden.

How accurate is automatic key detection?

Good, but never perfect. The usual misses are near ones: the relative major or minor, which shares every note, a key one step away on the Camelot wheel, or a single key for a song that changes key. Check the reading by playing the key's chords against the song, and trust your ear when they disagree.

Can I find the key of a song without downloading it?

Yes. Type the song's name or paste a streaming link into the Key finder. It reads the key and BPM from half a minute of the song and keeps nothing of it.

Why does my song show more than one key?

The song probably changes key, for example a last chorus that moves up a semitone or a tone. The Key finder colours the waveform by key over time and prints each key where it starts, so you can see where the change happens.

How do I tell if a song is major or minor?

Find the note that feels like home, then play the major and the minor chord on it along with the song. The one that sounds right gives you the mode. Happy or sad is a weak cue, because plenty of upbeat songs are in minor keys.