The (ex-totem?) Video player proposes the installation of gstreamer1.0-plugins-bad, but after installation there is no playback, nothing. When I try to open the .midi file again, the Video player comes up with the installation again and again. So I guess, this is not the right package.
UPDATE: Rythmbox isn't configured to play .midi files either.
VLC media player can do that for you given that the plugin for midi is installed.
sudo apt install vlc vlc-plugin-fluidsynth
After that you can play your midi library with VLC without installing timidity.
Open the terminal and enter:
sudo apt install timidity timidity-interfaces-extra
Enter your password, another prompt may appear type, Y and hit enter.
Go to your menu, you should now have an application called TiMidity++ launch it. In terminal would be timidity mymusic.mid.
In TiMidity++ go to File > load and redirect it the location of your midi file, select the file, then okay then play
The gstreamer method of playing MIDI is to use the sound card's sequencer to do so. However, many sound cards do not necessarily have an instrument for playing MIDI, these days. Instead, you will need to install a software sequencer, such as timidity to play the files.
I needed proper sound fonts.
sudo apt install fluid-soundfont-gm fluid-soundfont-gs
There is also a Firefox plugin now: MIDI Player.
If all you need is playing the occasional MIDI that comes up on web pages like on Wikipedia, this may be the simplest solution.
