Most chord finders ask you to click notes on a keyboard and then name the chord. This one works the other way round: you give it audio, and it tells you the chords. Upload a song, a demo or a quick recording of yourself playing, and the AI writes out the chord sequence, the quality of each chord (major, minor, diminished or augmented), any inversions it hears, and the Roman numeral for each chord in context. It explains what job each chord does, whether tonic, subdominant or dominant, notes where the harmony moves to a new key, and rates how complex the harmony is overall. The tonal center is named too, so the numerals make sense.
Example result
Input
A 45-second phone recording of an acoustic guitar playing the verse and chorus of an original song, with a vocal on top.
Output
Tonal center: D major. Verse progression (repeats twice): D | A/C# | Bm | G. Roman numerals: I, V6, vi, IV. The A/C# is a first-inversion dominant that walks the bass down stepwise from D to B. Chorus progression: G | D | A | Bm, then G | D | Em7 | A. Numerals: IV, I, V, vi, IV, I, ii7, V. The chorus opens on the subdominant, which gives it a lift compared with the verse. Chord qualities: all major and minor triads plus one minor seventh (Em7). No diminished or augmented chords. Key changes: none. The final A resolves back to D at the top of the next verse. Harmonic complexity: low to moderate. The descending bass in the verse is the most distinctive feature.
Scores
How it works
How Key & Chord Progression Analyzer works
- 01
Give it a recording
Sign in, open the analyzer and upload an audio file or record straight from your browser: a full track, a loop from your DAW or just you strumming the changes. You can choose which AI model does the listening.
- 02
Bass and chord tones
The model listens to the bass line and the notes stacked above it to name each chord and its quality. When the lowest note is not the root, it reports the inversion, such as C/E or G/B.
- 03
Function and numerals
Once the tonal center is clear, each chord gets a Roman numeral and a role. A progression like C, Am, F, G becomes I, vi, IV, V, with the V marked as the dominant pulling back home.
- 04
Changes and complexity
Finally it flags modulations, borrowed chords and secondary dominants, and gives a harmonic complexity rating so you know whether you are dealing with three chords or a jazz reharmonization.
Use cases
Who it is for
Learning a song by ear
Upload the track you want to cover and get the changes in order, including slash chords that are easy to miss when you are only listening to the top notes.
Songwriters naming what they played
Recorded a voice memo of an idea you improvised on piano? Run it and get the progression written down with numerals, so you can transpose it or show it to a bandmate.
Theory students
Check your own Roman numeral analysis of a piece against a second opinion, and see the harmonic function of each chord explained in plain language.
Producers and beatmakers
Identify the chords in a sample or loop before you write a bass line or layer a new part on top of it.
Tips
Get better results
- A solo guitar or piano is easier to read than a dense mix full of distortion and synth pads.
- Make sure the bass is audible; it is how inversions and slash chords are recognized.
- If a chord is labeled differently than you expected, check it against the bass note. Am7 and C6 share the same notes and differ mainly in which one sits on the bottom.
- Only need the key and not the chords? The key finder is quicker for that job.
Limitations
What it can't tell you
Chord recognition from audio is an AI estimate, not a transcription by a trained musician. Busy arrangements, heavy effects, detuned instruments and extended jazz voicings can produce a simplified or ambiguous label, and passing notes in a melody are sometimes read as part of the chord. Treat the output as a strong first draft and confirm tricky spots on your instrument.
Frequently Asked Questions
Key & Chord Progression Analyzer questions
Can I identify chords from an audio file?
Yes. That is exactly what this tool is for. Upload an MP3, WAV or other common audio file, or record in the browser, and the AI returns the chord sequence with each chord's quality, inversion and Roman numeral.
How is this different from a chord finder where I enter notes?
Note-entry chord finders need you to already know which notes are sounding. This chord detector starts from the sound itself, so it helps when you can hear the harmony but cannot pick out the individual notes, which is most of the time when learning by ear.
Does it detect key changes?
It reports modulations it hears, such as a final chorus that moves up a whole step or a bridge that shifts to the relative minor, and adjusts the Roman numerals to the new key. Brief borrowed chords are described as borrowed rather than as full key changes.
What are Roman numerals in chord analysis?
They describe each chord by its position in the key instead of its letter name. Uppercase numerals are major chords and lowercase are minor, so I, V, vi, IV is the same progression in any key. That makes it easy to transpose a song or compare it with other songs.
Will it give me exact timings for each chord?
The report lists chords in order and groups them by section, which is what you need to play along. It is not a bar-by-bar chart with timestamps, so for precise rhythm placement use the progression as a guide and count along with the recording.
Is there a way to try it before paying?
The AI analyzers run on a paid plan with monthly credits, and there is no trial. If you want a quick, in-browser check first, the key finder and pitch detector need no account; the pricing page lists the plans for the full chord analysis.
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Pitch Detector
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Instrument Detector
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Key & Chord Progression Analyzer uses credits from a paid LindaleAI plan. See pricing