Open Source Licenses

ScoreLens is built on work other people gave away. This page lists the components it ships with and the licences they are used under. Each licence text is available from the project's own repository.

Recognition server

Sheet music recognition uses homr, licensed under the GNU Affero General Public License v3.0. Our server runs a modified version of homr as a separate process: upstream homr plus optional hooks that export the engine's own intermediate results, with the same recognition model. The complete corresponding source of the modified program, including the exact version we run (commit bff19d3), is available from the scorelens-app/homr repository; it is derived from the original homr by its authors. For some pages the server also runs the unmodified upstream homr, the same way. The server also uses FastAPI (MIT), the Google Cloud client libraries (Apache-2.0) and Redis (BSD-3-Clause / RSALv2).

Score rendering and playback

• OpenSheetMusicDisplay — BSD-3-Clause
• smplr — MIT
• midi-writer-js — MIT
• fast-xml-parser — MIT
• qrcode-generator — MIT

Instrument sounds are from the Musyng Kite General MIDI soundfont as converted by the midi-js-soundfonts project, used under the Creative Commons Attribution-ShareAlike 3.0 licence. The app ships a subset of its samples (fewer notes per instrument, otherwise unchanged); that subset is distributed under the same licence. Sustain loop points are from goldst.dev/midi-js-soundfonts.

The piano is the Salamander Grand Piano V3 by Alexander Holm (sfzinstruments/SalamanderGrandPiano), used under the Creative Commons Attribution 3.0 licence; the app uses a reduced set of its samples (four velocity layers, shortened and compressed).

Clarinet, saxophone, horn, trombone, tuba, oboe and bassoon sounds are rendered from MuseScore_General (FluidR3 by Frank Wen, mono conversion by Michael Cowgill, adaptation by S. Christian Collins; MuseScore), MIT licence: copyright notices and licence text.

Application framework

• React and React Native — MIT
• Expo and its modules (application, asset, audio, camera, constants, crypto, file-system, font, haptics, image-manipulator, image-picker, linking, print, router, sharing, splash-screen, sqlite, status-bar, updates) — MIT
• @sentry/react-native (crash reporting) — MIT
• react-native-reanimated, react-native-worklets, react-native-gesture-handler, react-native-safe-area-context, react-native-screens, react-native-svg, react-native-webview — MIT
• @shopify/react-native-skia — MIT
• @noble/hashes — MIT
• react-native-vision-camera and react-native-vision-camera-worklets (camera capture) — MIT
• react-native-nitro-modules and react-native-nitro-image — MIT
• mixpanel-react-native (anonymous, opt-out analytics) — Apache-2.0
• react-native-purchases and react-native-purchases-ui (RevenueCat, subscriptions) — MIT

Typefaces

Unbounded and Golos Text are used under the SIL Open Font License 1.1, packaged by the expo-google-fonts project (MIT).

The music notation drawn on this website (noteheads, flags, rests, clef and time signature) uses glyph outlines from Bravura, © Steinberg Media Technologies GmbH, used under the SIL Open Font License 1.1 (licence text, Bravura repository).

Sample score

The sample piece included with the app is in the public domain. Its engraving was produced from a CC0-licensed MusicXML source.

If you believe something is listed incorrectly or is missing, write to hello@scorelens.app and it will be fixed.