Is It Legal to Convert a Song to MIDI? Copyright Facts Explained

Two separate copyrights in every song

A recorded song involves two distinct copyright layers, and both matter when you convert audio to MIDI:

• The composition copyright protects the underlying musical work — the melody, harmony, and lyrics as written. This belongs to the songwriter or their publisher.
• The sound recording copyright protects the specific recorded performance — the actual audio in the file. This belongs to the performer or the record label.

When you convert an MP3 to MIDI, the audio you feed in is a sound recording. The MIDI you get out captures information derived from the composition — note pitches and timing. The MIDI file does not reproduce the sound recording itself; it contains a sequence of note data. But the note data is derived from a copyrighted composition, which means the output can still implicate the composition copyright even though it does not copy the recording.

This distinction matters and it is also why the answer is not a simple yes or no. The two copyrights are independent: a song can have one copyright holder for the composition and a different one for the recording. Licensing one does not license the other.

What a MIDI file actually contains

A Standard MIDI File is a sequence of note events — note-on, note-off, pitch, timing, and velocity data. It does not contain audio. It does not contain the recorded waveform, the singer's voice, or the timbre of the instruments. When our converter produces a .mid file, it writes a track with a tempo setting (PPQ of 480, BPM of 120), note-on and note-off events mapped from the detected pitch contour, and a velocity value for each note. That is all the file contains.

Because MIDI contains note data and not audio, it is sometimes compared to sheet music rather than to a recording. A MIDI transcription of a melody is a representation of the composition, not a copy of the recording. This is relevant to the copyright question, but it does not automatically make the file legal to distribute — the composition is still protected.

Personal use versus distribution

What you do with the MIDI file matters more than the act of converting. The same conversion can be defensible for personal study and problematic for distribution:

The pattern: converting for yourself, in private, to learn from or practice with is on the lower-risk end. Converting to share, sell, or incorporate into something you release is on the higher-risk end. Where exactly the line falls depends on your jurisdiction and the specifics of your use.

Fair use and fair dealing

In the United States, the doctrine of fair use allows limited use of copyrighted material without permission for purposes such as criticism, comment, research, and education. Whether a specific use qualifies as fair use depends on four factors:

1. Purpose and character of the use — non-commercial, educational, and transformative uses are more likely to qualify as fair use than commercial uses that merely replicate the original.
2. Nature of the copyrighted work — creative works like songs receive stronger protection than factual works.
3. Amount used — converting a short melody fragment is different from converting an entire song.
4. Market effect — if the MIDI file substitutes for a product the copyright holder sells (such as official sheet music or a licensed MIDI file), that weighs against fair use.

Other jurisdictions have analogous doctrines — fair dealing in the UK, Canada, and Australia, for example — but the specifics differ. Fair use is a defense raised after a claim is made, not a permission slip. If you are relying on it, you are accepting some level of risk.

Derivative works

A MIDI transcription of a copyrighted melody is a derivative work under copyright law. A derivative work is one based on a preexisting work that has been translated, adapted, or otherwise transformed. The copyright holder of the original composition has the exclusive right to create and authorize derivative works.

This means that even though you created the MIDI file yourself using a tool, and even though the file does not contain audio from the recording, the note data it contains is derived from a protected composition. Making a derivative work for personal use is treated differently from distributing one. The personal-use question is where fair use or fair dealing comes in. The distribution question is more straightforward: distributing a derivative work without a license from the composition copyright holder is copyright infringement in most jurisdictions.

Public domain music

Music enters the public domain when its copyright expires. The rules for when that happens depend on the country. In the United States, compositions published before a certain date have entered the public domain. Sound recordings have their own separate timeline, and recordings of public domain compositions can still be under copyright.

If you convert a recording of a public domain composition — say, a Bach prelude performed and recorded recently — the composition is free to use, but the specific recording may still be protected. The MIDI file you produce from that recording would contain note data from a public domain composition, which is fine to use. But the recording you converted may not be free to redistribute in audio form.

If both the composition and the recording are in the public domain, converting the audio to MIDI is unproblematic on both layers.

Original recordings and your own work

If the audio is your own original recording — you wrote the melody and you performed or produced the recording — then you own both the composition copyright and the sound recording copyright. Converting it to MIDI is entirely within your rights. The MIDI file is your work product.

This is the case for many users of our converter: you hum a melody into your phone, convert it to MIDI, and use the result in your own project. The audio is yours, the melody is yours, and the MIDI file is yours. No third-party copyright is involved.

Our MP3 to MIDI converter is built for exactly this scenario. It processes the file in your browser using the Web Audio API — the file is decoded by decodeAudioData on your device, the pitch detection runs in JavaScript on your machine, and the MIDI bytes are generated locally. The file is never uploaded to a server, and no account is required. This matters for privacy and it also means the tool itself does not create or store copies of copyrighted audio.

What the tool does and does not do

It is worth being precise about what happens when you use this converter, because the technical behavior is relevant to the copyright question:

• The tool does not store your audio. The file is loaded into browser memory, decoded into an AudioBuffer, processed by the autocorrelation pitch detector, and then the MIDI bytes are generated as a Blob for you to download. No copy of the audio is sent to or stored on any server.
• The tool does not check copyright status. It cannot tell whether the file you give it is your own recording, a public domain work, or a copyrighted song. It processes whatever audio you provide.
• The tool does not watermark or identify the output. The .mid file it produces contains note data and nothing that ties it back to a specific source recording.
• The tool requires no login. There is no account, no tracking of what you convert, and no record of your activity stored anywhere.

The responsibility for what you convert and what you do with the result rests with you. The tool is a browser-based utility; it does what you tell it to do on your own device.

Practical guidance

Without giving legal advice, here is a practical framework for thinking about it:

• If the audio is your own original recording: Convert freely. You own the rights.
• If the audio is public domain on both layers: Convert freely. No copyright to infringe.
• If the audio is a copyrighted song and you want to study it or practice with it: Converting for personal, non-commercial use is on the lower-risk end, but the legal basis varies by jurisdiction. Do not redistribute the MIDI.
• If you want to use the MIDI in something you release publicly or commercially: You need to license the composition from the copyright holder or use a royalty-free source. A MIDI transcription of a copyrighted melody incorporated into your released track is an unlicensed derivative work.
• If you want to share the MIDI online for others to download: Distributing a MIDI transcription of a copyrighted composition without a license is copyright infringement in most jurisdictions, even if you created the transcription yourself and even if you do it for free.

How to stay on the safe side

1. Convert your own recordings whenever possible. If you want a MIDI version of a melody, record yourself humming or playing it and convert that.
2. Use public domain music if you need to transcribe existing works. Verify that both the composition and the recording are in the public domain in your jurisdiction.
3. If you convert a copyrighted song for personal study, keep the MIDI file to yourself. Do not upload it to MIDI archives, do not share it in forums, and do not include it in anything you publish.
4. If you need to use someone else's melody in a released project, get a mechanical license or a sync license from the composition copyright holder. The conversion tool does not grant you any rights to the underlying composition.
5. If you are unsure about your specific situation, consult a copyright lawyer. This page gives you the framework, not a ruling on your case.

What this tool is designed for

Our converter is designed for working with your own audio — a melody you hummed, a riff you played, a vocal line you recorded. You load the file in your browser, the converter detects the pitch contour using autocorrelation, and you get a .mid file you can open in a DAW or a piano roll editor. The whole process happens on your device with no upload and no login.

If you want to hear what the MIDI sounds like after conversion, you can run it back through MIDI to WAV to synthesize the notes and compare the result to your original recording. If the output is in the wrong octave or has spurious notes, see our guide on why your MP3 to MIDI sounds bad for troubleshooting.

Bottom line

Converting audio to MIDI is a technical process, not a legal status. Whether it is legal depends on the source material and what you do with the result. Convert your own recordings freely. Convert public domain music freely. Convert copyrighted songs only for personal use, and do not distribute the result. The tool processes everything in your browser and does not store or transmit your files, but the responsibility for what you convert and how you use the output is yours.