Capo, in one example
With a capo on fret N, every shape you play sounds N semitones higher than the shape's name. So to play a song in Eb with open shapes, put the capo on fret 3 and play C, G and Am. The song is unchanged: you only changed which shapes your fingers make.
| Song chords | Capo fret | Shapes you play | Why |
|---|---|---|---|
| Eb, Bb, Cm, Ab | 3 | C, G, Am, F | Subtract 3 semitones from each chord |
| F#, C#, D#m, B | 4 | D, A, Bm, G | Open D-family shapes |
| Bb, F, Gm, Eb | 3 | G, D, Em, C | The classic G-D-Em-C set |
| A, E, F#m, D | 0 | A, E, F#m, D | Already open except F#m (barre) |
The tool does this subtraction for you and ranks frets 0 to 7 by how much of the song sits on easy open shapes (C, A, G, E, D, Am, Em, Dm and common 7th and sus chords).
Why isolate the guitar first
In a full mix, the bass, keys and vocals all contribute notes, and the detector averages them. Pull the guitar out with the guitar extractor and the chord detector hears mostly what you are going to play. This matters most on songs where the guitar is the main harmony.
| Song | Best input |
|---|---|
| Acoustic singer-songwriter | The full mix usually works |
| Rock with a keyboard pad and bass | Guitar stem |
| Pop with synth chords | Try the "other" stem; the guitar may be absent |
| Two guitars, one lead, one rhythm | Guitar stem, then ignore single-note passages |
What you get and what you do not
- Chord names with start times, synced to the player, in the shape names for your capo.
- Key and tempo estimates.
- Transpose up to six semitones either way, for singing in a better range.
- A .txt chart with timestamps that records the capo fret.
You do not get finger diagrams, strumming patterns, tabs or exact voicings. The shapes are chord names to look up: the tool does not know whether the original used a barre chord, an open one or a different inversion. Accuracy is approximate, and sus and 7th chords are the likeliest to be wrong, so check them by ear.
Tips for beginners
- Start with the first verse: if the first four chords repeat, you have most of the song.
- Learn the shapes slowly: slow the audio down first with the pitch changer (speed without changing pitch), then drop the slowed file in.
- If a chord sounds clashing with the recording, try the plain version: Gsus4 to G, or G7 to G.
- If the song is too high or low to sing, transpose first, then choose the capo, in that order.
Frequently asked questions
How do I find guitar chords from an MP3?
Drop the MP3 into the tool above. It detects the chords in your browser and shows them on a timeline you can follow while the song plays.
How does the capo suggestion work?
For each fret from 0 to 7 it lowers every chord by that many semitones, then measures how much of the song falls on easy open shapes. The frets with the highest share are offered as buttons.
Does the song change key when I add a capo?
No. The song sounds the same. The capo only changes which shapes you play to make those sounds.
Is it better to extract the guitar first?
Often yes. A guitar stem has less drum and vocal noise, so chords are steadier. Use the guitar extractor, then drop the stem here.
Does it give chord diagrams or tabs?
No. It gives chord names and timings only. Look up diagrams for the shapes you do not know.
Is it free and private?
Yes. It runs in your browser, nothing is uploaded and there is no sign-up or cap on songs.
Why does it show Dsus4 or G7 when I hear a plain chord?
Passing notes can look like a suspension or a seventh. Try the plain triad; if that sounds right, use it. The automatic detection is approximate.