FluidSynth as a background service

Required if you need MIDI support in any of your Wine/Proton software

Install FluidSynth

sudo rpm-ostree install fluidsynth

If you have vlc layered you should also install vlc fluidsynth plugin to play midis in vlc

sudo rpm-ostree install vlc-plugin-fluidsynth

Now reboot

systemctl reboot

Download gm.sf2 from here https://musical-artifacts.com/artifacts/713 and put it somewhere e.g. /opt/soundfonts/

Edit fluidsynth configuration:

sudo vim /etc/sysconfig/fluidsynth

# Mandatory parameters (uncomment and edit)
SOUND_FONT=/opt/soundfonts/gm.sf2

# Additional optional parameters (may be useful, see 'man fluidsynth' for further info)
OTHER_OPTS='-a pipewire -r 48000 -z 512'

Enable fluidsynth user service and verify status:

systemctl enable --now --user fluidsynth.service
systemctl --user status fluidsynth.service

Do not use alsa or pulseaudio outputs with fluidsynth because they don't work properly and cause the MIDI player to randomly break.

You should also make sure that you definitely set frequency (-r 48000) and audio buffer size (-z 512) to avoid audio cracking/distortion issue.