Try it out: https://midivis.ryusei.dev/
Make sure to use browsers which support Web MIDI API, such as Google Chrome or Microsoft Edge.
Mozilla Firefox is currently not supported. See: https://bugzilla.mozilla.org/show_bug.cgi?id=836897
- Alt+S: Toggle "use sharp notes"
- Alt+1: Change color scheme to "Monotone"
- Alt+2: Change color scheme to "Chromatic"
- Alt+3: Change color scheme to "Circle of fifth"
- Alt+4: Change color scheme to "Axis system"
- Alt+5: Change color scheme to "Quintave"
- Ctrl+,: Open Settings