The Technology of MIDI
- MIDI Messages
- MIDI Transports
- Standard MIDI Files
Part Three: Standard MIDI Files
When MIDI messages are stored on disks, they are commonly saved in the Standard MIDI file format, which is slightly different from native MIDI protocol, because the events are also time-stamped for playback in the proper sequence. Music delivered by MIDI files is the most common use of MIDI today. MIDI is the primary source of music in many popular PC games and CD-ROM entertainment titles, and thousands of MIDI files are available on the Internet for recreational use. Just about every personal computer is now equipped to play Standard MIDI files.
One reason for the popularity of MIDI files is that, unlike digital audio files (.wav, .aiff, etc.) or even compact discs or cassettes, a MIDI file does not need to capture and store actual sounds. Instead, the MIDI file can be just a list of events which describe the specific steps that a soundcard or other playback device must take to generate certain sounds. This way, MIDI files are very much smaller than digital audio files, and the events are also editable, allowing the music to be rearranged, edited, even composed interactively, if desired.
With the recent introduction of the Downloadable Sounds (DLS) format, MIDI files can now be combined with standardized samples of musical instruments, sound effects, or even dialogue, which are used to recreate an exact copy of the sound intended by the composer. MIDI files with DLS (in RMID or XMF format) are the ideal solution for composers of all kinds who want the predictable playback of digital audio, but also need the compactness and/or interactivity of Standard MIDI Files for delivering their music.