MIDI
MIDI, or Musical Instrument Digital Interface, is a musical format that sends song data directly to the sound card to be synthesized and relayed back to the user. MIDI is commonly used in fangames due to its extremely small file size compared to WAVE and MP3 sound formats. However, MIDI sounds tend to be highly computerized and unrealistic. While most new game consoles (such as the Nintendo DS) have different sound cards to make up for this, personal computers still remain sounding highly computerized.
An alternative method to getting a higher quality sound has been replacing the General MIDI sound bank with other higher quality sound banks and canvases, though this method is specific to a user's sound card hardware.
Due to the low-quality music MIDI usually produces, some MFGGers have begun using the Ogg Vorbis sound format for music in their fangames instead.