Terms of Use for Melodex
Melodex: Hum to Sheet Music Published by OFO Labs
Last Updated: September 2026
Please read these Terms of Use carefully before using Melodex. By downloading or using the app, you agree to these terms.
Acceptance of Terms
By accessing or using Melodex, developed and published by OFO Labs, you agree to be bound by these Terms of Use. If you do not agree, do not use the app.
The App
Melodex records a hummed, sung or whistled melody and writes it out as sheet music. Everything is computed on your device. It makes no network requests.
What we promise about the transcription, and what we do not
We think this belongs in the terms rather than only in the marketing.
Melodex tracks pitch with probabilistic YIN, decoded across the whole take so that a single misread frame cannot survive as an octave error. It finds note starts from spectral flux and from pitch changes, estimates tempo by fitting a grid to your onsets, and quantizes the rhythm with a cost that prefers plausible written values over exact ones. It detects the key with the Krumhansl-Schmuckler profiles, spells accidentals from that key, and engraves the result with correct clefs, beaming by beat group, ties across barlines and rests that fill each bar. Our test suite generates a score, synthesizes audio from it, feeds that audio back through the whole pipeline and requires the recovered notes to match the originals note for note.
That is a model, and a model is not your voice in your room. A transcription is an interpretation. Melodex writes one line of melody at a time, which is what humming is: it does not transcribe chords, several instruments at once, or a whole band recording. Background noise, a very breathy or very quiet voice, heavy vibrato, deliberate pitch bends and rubato all make the answer less certain. A note sung between two pitches has to be written as one of them.
That is exactly why every note is editable. Tap a note to raise, lower, lengthen or shorten it, set the key yourself, and change the tempo. Please check the transcription before you rely on it, particularly before you hand it to another musician or print it.
Your music is yours
Anything you hum, record or write in Melodex belongs to you. We claim no rights over it, we do not see it, and we cannot use it. The exports the app produces are yours to do anything with.
The purchase
Melodex writes the first eight bars of every take at no cost, with full editing and playback of those bars and unlimited takes in your library. One optional purchase, Melodex Pro, unlocks unlimited bars, the PDF, MusicXML, MIDI and image exports, transposition, and time signatures other than 4/4.
It is a one-time purchase, not a subscription. There is nothing recurring and nothing to cancel. Purchases are processed by Apple; refunds are handled by Apple under their own terms, and we cannot issue one ourselves.
If you do not buy, or if you restore on a new device before the purchase is recognised, your takes are never lost. The music you already recorded stays readable and playable up to the free ceiling, and unlocking restores the rest.
Third party content
The music glyphs are drawn with Bravura by Steinberg Media Technologies, used under the SIL Open Font Licence 1.1 and bundled unmodified together with its licence. The sample melody included for people who decline microphone access is "Ah! vous dirai-je, maman" (1761), which is in the public domain.
Acceptable use
Do not attempt to decompile, reverse engineer or redistribute the app. Do not use it to infringe anyone else's copyright: transcribing a recording you do not have rights to does not give you rights to it.
Disclaimer
Melodex is provided "as is", without warranty of any kind. To the fullest extent permitted by law, OFO Labs is not liable for any loss arising from your use of the app, including any consequence of relying on a transcription without checking it.
Changes
We may update these terms. Material changes will appear here before they take effect.
Contact
ofolabs@gmail.com