How to Find the Key of a Song
The fastest way: drop your audio file below. BeatKey detects the musical key (and BPM) in under 5 seconds - free, private, no account needed.
Detect Key Now →Find a Song's Key in 3 Steps
- Go to beatkey.app
- Drag and drop your audio file (MP3, WAV, FLAC, AIFF, M4A)
- Read the musical key, BPM, and Camelot code instantly
Your file never leaves your browser - all analysis happens locally using WebAssembly.
What Is the Musical Key of a Song?
A song's musical key is the set of notes (scale) that the track primarily uses - and the root note that feels like "home." For example, a track in C Major uses the C major scale and resolves back to C.
Keys come in two flavors: major (bright, uplifting) and minor (darker, more emotional). Each key has a relative minor/major counterpart - A Minor and C Major share the same notes.
Why Knowing the Key Matters
Harmonic Mixing (DJs)
Mix tracks in compatible keys so they sound musical together. The Camelot Wheel makes this visual - adjacent numbers = compatible keys.
Playing Along
Guitarists and keyboardists use the key to improvise solos or add their own parts without clashing with the original track.
Sample Flipping (Producers)
Chopping a sample and building chords around it requires knowing its key so your added elements don't clash.
The Camelot Wheel - Harmonic Mixing Made Simple
The Camelot Wheel assigns each musical key a number (1–12) and a letter (A for minor, B for major). BeatKey shows this code in the results, so you can immediately see which other tracks will mix without harmonic clashes.
Mixing rules:
- Same number, same letter (e.g. 8B → 8B) - perfect match
- Adjacent numbers, same letter (e.g. 8B → 7B or 9B) - energy shift, still harmonic
- Same number, different letter (e.g. 8B → 8A) - relative minor/major, very compatible
Other Ways to Find a Song's Key
By Ear
Hum along to find the lowest note that sounds "finished." That's likely your root. Then check if it sounds major or minor. Accurate for trained musicians; unreliable for everyone else.
Checking Music Streaming Metadata
Spotify and Apple Music store key data internally (often from Echonest/AcousticBrainz analysis), but they don't always surface it publicly. Third-party databases like Tunebat aggregate this for popular tracks.
DAW Key Detection (Ableton, FL Studio)
Modern DAWs can estimate a clip's key. Right-click an audio clip in Ableton Live → "Detect Pitch" to get an estimate. Less reliable on full mixes - works better on isolated stems.
BeatKey Recommended
Drop your file into beatkey.app. Get key, BPM, and Camelot code in seconds - works on full mixes, stems, and loops. 100% private.
Frequently Asked Questions
How accurate is BeatKey at detecting the key?
BeatKey uses Essentia's KeyExtractor algorithm - the same tech used in professional audio analysis tools. Accuracy is high for tonal tracks (most pop, EDM, hip-hop, rock). Complex jazz or atonal music may return lower confidence scores.
Does BeatKey upload my audio file?
No. Everything runs locally in your browser using WebAssembly (WASM). Your file is never transmitted to any server - not even BeatKey's servers.
What audio formats does BeatKey support?
MP3, WAV, FLAC, AIFF, M4A, OGG, AAC, and most other common audio formats. If your browser can play it, BeatKey can analyze it.
What's the difference between the key and the BPM?
The key is the harmonic center - the scale and root note. BPM (beats per minute) is the tempo - how fast the track moves. BeatKey detects both simultaneously.