This experimental Web MIDI application is normally tested in the latest version of Chrome on Windows 10.
I will be testing it again on Firefox, when they have completed their implementation of the Web MIDI API.
Note that:

• The ResidentWAFSynth (a software MIDI output device) can play all the scores in this application,
  so the Web MIDI API only really needs to be implemented by the browser in order to access a hardware MIDI input device. This synthesizer is also used by three other applications:
  • WebMIDISynthHost (GitHub, application)
  • SimpleWebAudioFontSynthHost (application)
  • ResidentWAFSynthHost (GitHub, application)
• The ResidentSf2Synth uses a soundFont containing only a single GM Grand Piano preset (to save loading time). It can therefore only play the following scores:
      Pianola Music (1967), Study 1 (2005), Erratum Musical I-VIII (2019) and the Three Crashes (2019).
  This synth is also used by two other applications:
  
  • WebMIDISynthHost (GitHub, application)
  • SimpleSoundFontSynthHost (application)
• On Windows, the free Virtual MIDI Synth plugin can also be used to play any of the available scores.

ji www april 2020.