Well, I finally got Firefox to play MIDI files using a Soundfont of my choice. Previously, I showed How to Make MIDI Files Sound Better in Windows 7. Well, this doesn’t work in Windows 10 mainly because Microsoft removed the MIDI Mapper functionality and the MIDI playing plugins that used to work in Firefox no longer do. Anyway, here’s what I did for Windows 10.

First thing in Firefox is to install the MIDI Player extension by Jazz-Soft. Then, install the Jazz-MIDI extension in Firefox. This is all you do with Firefox itself. The next two items are separate programs that run in Windows. You’ll need to restart Firefox after installing the other programs.

The two items are from CoolSoft. The first is their VirtualMIDISynth program which allows you to choose which Soundfont(s) to use and which MIDI device to play through (more on this later). For now, go ahead and install their MIDIMapper plugin. This is the replacement for the removed Windows MIDI Mapper.

Once MIDIMapper is installed, run it and choose VirtualMIDISynth #1 as the default MIDI device as seen below. You might have to run VirtualMIDISynth first but I don’t think so.

Now that this done, run VirtualMIDISynth’s configuration and go to the MIDI Mapper tab and set VirtualMIDISynth #1 as the default MIDI Out device as seen below.

At this time you’ll want to set your default Soundfont to use in the Soundfonts tab as seen below. I happen to like the WeedsGM3 General MIDI Soundfont.

At this time, you should be able to play a MIDI file within Firefox and it will utilize the Soundfont you chose. If you click one of the  icons on my General MIDI page then you’ll see a window like the following pop-up.

Note: this will also effect any program in Windows that can play a MIDI file. Happy listening! 🙂