SMF is the extension of files used by the Digital Musical Instrument Interface (MIDI). SMF is a format used for the exchange of musical data between MIDI-compatible devices. The content of such a file is not typical audio data, but properly defined song parameters on the basis of which the song can be played. These include sound values, volume, and other parameters.

SMF files come in two variants: with one track or with division into sequences saved on separate tracks.