To convert a MIDI file to OGG on Linux, use the LMMS music-making application. Import a MIDI file by opening the Import menu. This is the Project->Import menu option. Then export the MIDI file to an OGG format file with default settings.
This will create a very high-quality rendering of a MIDI file, this uses high-quality instruments and can make old MIDI music sound incredible. Especially music from Doom. This is great for Wolfenstein music as well. This is a conversion of one of the music tracks from Wolfenstein 3D.
This is a song from Wolfenstein Spear of Destiny. This is also used in the Stalker mod New Arsenal 6, in Lab X-14. But this shows the quality that you can get from converting a MIDI file this way. LMMS does not seem to be able to export as a MIDI file, but is a very good application for making music on Linux.
