MIDI audio file
SMF is a file extension for an audio file in the MIDI format. SMF stands for Standard Midi Files. SMF files contain the codes for a musical event that include the start of a note, its pitch, length, volume, and musical attributes, such as vibrato. SMF files do not contain audio signals or media, and as such are used to save space on the hard disk drive. SMF files can be opened by Windows Media Player, and Quicktime Player. SMF files can be created by digital sequencing software such as Digital Performer, Cubase, and Sonar.
MIME type: audio/x-midi, audio/mid
Learn more about .SMF files:
Visit the Quicktime web page.
Learn about Recording at ITKnowledgeExchange.com.