# Mp3tomidi — Export a chord progression as CSV

After detection you can save a CSV that opens in any spreadsheet, useful for charts, teaching notes, or a rough arrangement log. Download names, start times, end times, durations, and confidence.

## What it is

A chord overlay on a webpage is easy to lose. The detector at https://mp3tomidi.art/chord-detection/ can export the full progression as a CSV containing chord names, start and end times, durations, and confidence scores, which opens in a spreadsheet. That is practical for a rehearsal chart, a lesson handout, or comparing two takes of the same song. The algorithm runs entirely client-side. Because it labels frames independently, a key change can show up as a shift in the chord list rather than a single global key. Still, treat ambiguous voicings with care and listen through the recording. The product page on [online chord finder](https://mp3tomidi.art/chord-detection/) has the current details. Start from https://mp3tomidi.art/.

If you came for Chord Detection, that is the tool this note emphasizes. export chord chart as CSV You can still move to the other free tools on the same site without creating an account.

## Key features

- The free MP3-to-MIDI conversion transcribes the first 30 seconds of a file; uploads may be up to 50 MB and from 1 second to 10 minutes long.
- A MIDI editor lets you change pitch, timing, and velocity on a piano roll, with undo, then download a Standard MIDI file.
- Core tools are free, with no signup and no credit card, and they run in Chrome, Firefox, Safari, and Edge.
- MP3 and other audio can be turned into a Standard MIDI Type 0 file with a piano-roll preview, using Spotify's Basic Pitch model in the browser.
- Sheet-music tools build a MusicXML 3.1 draft from MIDI or from audio, which you can finish in MuseScore or a similar app.
- A 6-stem splitter runs a client-side HT-Demucs model (vocals, drums, bass, guitar, piano, and other). The first visit downloads about 147 MB of weights.
- MIDI to audio can render the first track of a Format 1 file with piano, synth, or FM oscillator sounds to WAV in the browser, or to other formats with a cached ffmpeg WebAssembly encoder.
- Chord detection labels nine qualities across twelve roots, plus N/C, and can export a CSV of timings and confidence.
- The BPM and key finder typically reports tempo within 1–2 BPM on steady-tempo tracks, with a confidence score, using the Web Audio API.

## How to use it

1. Open https://mp3tomidi.art/ and pick the tool you need, such as MP3 to MIDI, BPM and key, chords, stems, the MIDI editor, or sheet music.
2. Load an audio or MIDI file in the browser. Most tools process the file on your device.
3. Review the preview: a piano roll for transcription, a tempo and key reading, a chord list, or separated stems.
4. Edit notes if you need to, then download MIDI, audio, CSV, or MusicXML.
5. Check the result by ear or in your DAW; these outputs are drafts for reference, not finished professional transcriptions.

## Use cases

- **DJs:** Check BPM and key on a track without installing a desktop app.
- **Musicians:** Turn a practice take into editable MIDI notes.
- **Producers:** Sketch a melody or split a reference mix into stems before arranging.
- **Students:** Get a first-draft score or chord list from a recording.

## Honest limits

- MIDI-to-audio uses oscillator sounds, not sampled VSTs.
- Core tools are free with no signup and no credit card; do not expect a published paid checkout on the public site.
- Results are drafts for reference, not professional transcriptions; dense mixes may need a stem split first, and every transcription should be checked by ear.
- The site does not advertise a public API, and it is not a full DAW replacement.
- The free MP3-to-MIDI conversion covers only the first 30 seconds of a file, not the whole track.
- The stem splitter is a local HT-Demucs build, not an official Meta Demucs service, and the first visit downloads a large model.
- The MIDI-to-sheet preview is read-only; finish the score in another notation app.

## Summary

mp3tomidi is a free browser toolkit for MP3 to MIDI conversion and related music tools. It is most useful when you treat the output as a draft and stay within the limits above. Start from https://mp3tomidi.art/.