Hear the harmony.
A little Fourier. A little music theory. Your ears decide.
WAV · MP3 · M4A* / 8 MB · 2 min max
*M4A depends on your browser. Nothing is uploaded.
Choose your clip, or explore four bars of Bach.
Your sound goes here.
Best with clear piano, guitar, or sustained chords.
Up to 30 seconds at a time. Changing the range needs a new analysis.
Sound → frequencies → pitch classes → possible chords
Possible harmonies
Select a second to inspectOne-second smoothing · boundaries are approximate · “?” means unresolved
What do these bars mean?
The tallest bar is scaled to fit; orange marks the suggested chord tones. Each bar combines spectral peaks near the same note name in different octaves. Values are normalized to sum to 1; they are relative evidence, not volume or certainty. A tall E bar could be an E note—or a harmonic of another note. Black keys use a single spelling (C♯, E♭, F♯, A♭, B♭).
Where feels like home?
Key-profile correlation, not probability. A short clip can fit several keys.
Let's talk about this.
Bring the evidence back to Hermes. Ask about a chord, a change, or what your ear hears differently.
Evidence-derived explanations, not an AI chat. No chat endpoint or cloud inference.