SoundFont by jh (author identified in the file metadata), used to play the piano.
Free work: you may copy, distribute and modify it under the terms of the Free Art License 1.3. Copies and modified versions remain under the same or a compatible license.
The file is used unchanged and you can download the original from this site: steinway.sf2.
SoundFont synthesizer in the browser.
Camera hand tracking, running on your device.
Sheet music PDF reader.
Server-side sheet music recognition. Source code is available at the linked project.
Server-side piano-to-MIDI transcription.
Audio-to-MIDI transcription in the browser using TensorFlow.js and Tone.js MIDI.
MP3 encoding for audio export. It is loaded as a separate file (lame.js) and can be replaced with a modified version.
Fonts used in the interface.
From Bach to Joplin, Chopin to Debussy: the classical pieces come from the Mutopia Project. The composers’ works are in the public domain, and their transcribers have released the scores into the public domain (each piece’s license was checked before inclusion).
Other pieces are traditional or public-domain melodies, arranged for this site with simplified accompaniment.