Piano chord finder — get the chords from any piano recording.
For pianists who want to chart their own recordings, harmonise a classical score, or reverse-engineer the comp under a jazz melody. Upload an MP3 or WAV — get a chord chart with timing, key and tempo, ready to print or export.
Why finding chords on piano is its own problem.
On guitar, a chord is almost a physical object. A C major has a shape — open position, third fret barre, eighth fret — and once you know the shape, you can name what your hand is doing without hearing it. Piano refuses to be that tidy. The same C major can live in dozens of registers and voicings: root position C-E-G in the right hand, first inversion E-G-C, second inversion G-C-E, an open shell with C in the left and E-G in the right an octave up, a wide jazz voicing with C in the bass and a rootless 3-7 comping shape above. All of them are “C major” on a chord chart. None of them look or feel the same under the hands.
Then there are the two hands. A guitarist plays one harmonic instrument; a pianist plays two, and they are independent. The left hand may walk a bass line that briefly stops belonging to the chord overhead — passing tones, neighbour notes, a 10th that implies a different inversion than the right hand suggests. A pure chord finder that watches only the average harmony of the moment will quietly miss the story the bass line is telling. Pianists know this intuitively: the chord symbol is a summary, not a transcription.
Piano also has density that no fretted instrument can match. Six strings is a ceiling on guitar; on piano you can sound seven or eight notes at once with two hands, more if the sustain pedal is down and overtones are still ringing from the previous bar. That density is wonderful for harmony — colour tones, voice leading, suspensions — and brutal for any system that has to recover a chord name from an audio signal. The chord is there; it is just buried in three octaves of bloom. The sustain pedal in particular makes chord boundaries fuzzy: the C from beat one is still audible halfway through the F chord on beat three, so the pipeline has to weigh recent harmony against ringing harmony.
Finally, register changes meaning. A close-voiced triad in the middle of the keyboard sounds like a chord; the same notes packed below middle C sound muddy and ambiguous, and the same notes spread across three octaves stop sounding like a single chord at all — they start sounding like a texture. Good piano chord detection has to handle all three cases and report the harmony a musician would actually write down.
From piano audio to a chord chart in three steps.
We report the chord (e.g. “C”), not the specific voicing the pianist played. That is a deliberate scope choice — full polyphonic transcription is a separate, harder problem. What you get is the harmony layer, fast and exportable.
- 01
Upload your piano recording
Drag in an MP3 or WAV — a solo piano demo, a piano-and-vocals scratch take, a section of a classical performance, a jazz trio bounce. Up to 50 MB and roughly 10 minutes per file. No installs, no account required for your first analysis.
- 02
ChordSonic’s pipeline analyses the audio
The audio pipeline isolates the harmonic content, tracks the beat grid, estimates the key, and matches what it hears against a chord vocabulary. On piano-heavy material the cleanest signal usually comes from the right-hand register; the left hand and pedal contribute context. The whole job runs in seconds to a minute or two depending on length.
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Get a chord chart with timing and key
Output is a timeline of chord blocks with start and end times, the detected musical key, and the tempo in BPM. Scrub through to verify each chord by ear, transpose the chart up or down, and export to TXT, CSV or JSON for your DAW, notation software or a printed lead sheet.
Four things pianists actually use it for.
Harmonising classical lead sheets
Pull a recording of a Bach chorale, a Chopin prelude or a Schubert lied and recover the functional harmony underneath. Useful for jazz pianists learning to reharmonise classical pieces, for teachers building analysis worksheets, and for anyone who wants to learn the harmony of a piece faster than reading every note off the staff.
Reverse-engineering jazz comping
Drop in a Bill Evans solo or a Brad Mehldau trio cut and get the chord changes the comp implies. The voicings on the page won’t match what the pianist did — they are a summary — but the changes are right, and that is exactly what you need to start practising over the form in your own voicings.
Capturing your own piano demos
Record a phone voice memo at the piano while writing a song. Upload it. Get a chord chart you can hand to a bandmate, drop into a DAW as marker text, or paste into a lyric sheet. This is the use case where ChordSonic earns its keep for working songwriters who don’t want to transcribe their own scratch ideas by hand.
Transcribing piano covers
If you learn by ear from YouTube piano covers, you already know the rewind-and-guess cycle. Pull the audio, upload it, and start the cycle 80% of the way done. You still verify by ear — that is unavoidable for ambiguous voicings — but the chord skeleton is already there.
Honest limits.
Recovering chords from a piano audio signal is a hard problem and we want to be honest about it. On clean solo piano with moderate texture, accuracy on common major, minor and seventh chords lands around the mid-80% range. On dense Romantic-era writing, jazz with extended voicings, or piano sitting under a band mix, accuracy drops — sometimes considerably. The timeline always lets you scrub and correct, so think of the result as a strong first draft, not a finished transcription.
We also report chord names, not notation. You get the harmony with timing — chord blocks, key, tempo, exportable to TXT, CSV and JSON — but not staff notation, not MIDI of the actual notes played, not articulation marks, not pedal markings. For full note-by-note piano transcription you want a sheet-music transcription product; for the chord skeleton, this is the right tool. Many pianists use both side by side: ChordSonic for the bar-by-bar harmony, a notation tool for the specific notes and rhythmic details they want to capture on the staff.
And one last honest note: chord-name ambiguity is real on piano. A close-voiced D-F-A could read as Dm in one bar and as the upper structure of a Bb-major triad in the next; the musical context decides. We pick the reading that fits the detected key and the surrounding harmony, but you remain the final judge — especially when the piece modulates or sits in a deliberately ambiguous tonal space.
Piano chord finder, answered
Will it detect inversions and specific voicings?
No. ChordSonic reports the chord — C major, F# minor, Dm7 — not the specific voicing or inversion the pianist played. A root-position C-E-G, a first-inversion E-G-C, a rootless left-hand quartal, and a wide two-handed C2 + E4-G4-C5 are all reported as some flavour of C major because that is the harmony the listener hears. If you need note-level transcription with the actual register and fingering, you want a polyphonic transcription product that outputs MIDI or sheet music. We give you the harmony layer; you choose the voicing.
Does it work for classical piano?
Yes, with caveats. Solo classical recordings — Chopin nocturnes, Bach inventions, Debussy preludes — are well within range, especially when the texture is relatively clear and the tempo is moderate. Where it gets harder is dense Romantic-era writing (think Liszt etudes or thick Brahms chorales) where so many notes are sounding at once that even human ears split on the analysis. For lead-sheet harmonisation of a classical piece — say, finding the underlying functional harmony of a Schubert lied — ChordSonic is a strong starting point.
Can I get sheet music output?
Not from ChordSonic. We export a chord chart with timing — TXT, CSV or JSON — which is everything you need to compile a lead sheet, drop chord markers into a DAW or hand a session musician a chart. For staff notation with notes, rhythms and dynamics, you want a dedicated sheet-music transcription product. Many pianists pair us with notation software: ChordSonic gives you the chords and bars, you write the melody and inner voices on top.
How does it handle piano with other instruments?
Better than you might expect, because the pipeline does source separation before chord matching — so a piano-and-vocals track or a full-band arrangement gets cleaned up first. Accuracy is generally lower than on solo piano because the harmony information is now split across instruments, and some chord tones may be living in the bass or the horns rather than the piano. If the piano is the dominant harmonic instrument in the mix, results stay close to solo-piano quality. If the piano is decorative under a thick guitar bed, expect more correction work.
Is there a piano-specific version of ChordSonic?
No — and on purpose. There is one ChordSonic pipeline; it works on any audio. The reason this page exists is that pianists tend to search for chord finders differently, and the use cases for a pianist (harmonising a classical score, reverse-engineering a jazz comp, capturing a piano demo) are worth talking about specifically. But under the hood it is the same chord detection as the guitar player and the producer use. Piano is the recording, not a special mode.
Drop a piano track. Get the chords.
MP3 or WAV, up to 50 MB. Chord chart, key and tempo in seconds. Free, no credit card, exportable to TXT, CSV and JSON.