What the tool actually reads
The tool receives note events from the on-screen piano, the computer keyboard or a connected MIDI keyboard. It works with pitch classes such as C, C♯, D and E♭. Octave and loudness do not decide the suggested key.
No microphone or audio upload is required. The note workflow is processed in the browser.
How Version 2 suggests a key
Version 2 recognises an exact major or minor triad from three different pitch classes. For example, C–E–G is recognised as C major and A–C–E as A minor.
The display also shows a related major/minor context. That is a starting point, not proof of the key of an entire song: use the bass, chord progression, cadence and melodic resolution to confirm the tonal centre.
How to decide between relative major and minor
C major and A minor contain C, D, E, F, G, A and B. The difference is where the music feels settled.
- G or G7 resolving to C supports C major.
- E or E7 resolving to Am supports A minor.
- A bass line ending on C or A is strong evidence.
- A short unaccompanied melody may remain genuinely ambiguous.
Privacy and known limits
You do not need to upload a client demo. Browser settings may be stored locally. Optional analytics or advertising cookies should be enabled only after consent.
- Borrowed chords, modes, blues notes and modulation cannot be resolved from a single triad.
- One triad does not reveal the key of a complete song.
- Enharmonic spelling is simplified.
- The generator does not know the real chord beneath every syllable.
Questions and answers
Does it analyse MP3 or WAV?
No. The current version analyses notes you play or enter.
Can one note prove a key?
No. One note can set a manual starting point only.
Why are two keys displayed?
Relative major and minor share the same pitch collection.
Is generated harmony ready to record?
Treat it as a sketch and check every sustained note against the chord.