Definition of MIDI
MIDI stands for Musical Instrument Digital Interface. But it is not a tangible object, a thing to be had. MIDI is a communications protocol that allows electronic musical instruments to interact with each other. History of MIDI MIDI originated in 1980's by companies manufacturing electronic instruments (eg. music synthesizer) in a effort to standardize exchange of real time information between musical instruments. Instead of recording sound waves as in WAVE format, information such as "middle C key was just strongly pressed", "a key was just released", ... "change to 12th timbre" are encoded. Popular and avant-garde performers alike desired to "layer" their new sound creations, to play two sounds to- gether to create a "larger" sound. Though this was possible to some extent in a multi-track recording studio, layering could not be realized on the road. A few synthesizer design technicians from different manufacturers then got together to discuss an idea they shared. They jotted a few notes, considered a few options, and scuttled back to their design labs to create this communication method. They revealed their results at the first North American Music Manufacturers show in Los Angeles in 1983. The simple demonstration connected two synthesizers, not manufactured by the same company, with two ca- bles. A representative from one company then played one of the synthesizers while an amazed audience heard both sound. The process was then reversed to demonstrate the two-way nature of the communication. Other variations were illustrated, and the rest is music history. The Method of MIDI Much in the same way that two computers communicate via modems, two synthesizers communicate via MIDI. The information exchanged between two MIDI devices is musical in nature. MIDI information tells a synthe- tizer, in its most basic mode, when to start and stop playing a specific note. Other information shared includes the volume and modulation of the note, if any. MIDI information can also be more hardware specific. It can tell a synthesizer to change sounds, master volume, modulation devices, and even how to receive information. In more advanced uses, MIDI information can too indicate the starting and stopping points of a song or the metric position within a song. More recent applications include using the interface between computers and synthesizers to edit and store sound information for the synthesizer on the computer. The basis for MIDI communication is the byte. Through a combination of bytes a vast amount of information can be transferred. Each MIDI command has a specific byte sequence. The first byte is the status byte, which tells the MIDI device what function to perform. Encoded in the status byte is the MIDI channel. MIDI opera- tes on 16 different channels, numbered 0 through 15. Only the status byte has the MIDI channel number enco- ded. All other bytes are assumed to be on the channel indicated by the status byte until another status byte is received. Some of these functions indicated in the status byte are Note On, Note Off, System Exclusive (SysEx), Patch Change, and so on. The Note On status byte tells the MIDI device to begin sounding a note. Two additional bytes are required, a pitch byte, which tells the MIDI device which note to play, and a velocity byte, which tells the device how loud to play the note. Software / Sequencer history Although there were such things as analog sequencers, the sequencer didn't really come into its own until the invention of MIDI. A sequencer allows you to record, edit, and play back the parameters of a musical perfor- mance. The basic concept is that of a player piano or another instrument A sequencer does not record sounds in any way. Instead, it records the MIDI data. When you play back the sequence, your sound module will play the notes with the same timing and dynamics that you gave them when you recorded. Why record this way, instead of using tape? Editing. Once you record a track to analog tape, there is little you can do to change it, other than cutting and pasting sections of tape. With a MIDI performance, you can change it in any way you like, after the fact. You can: change the sound from an instrument to another; transpose the the pitch without altering the speed; change the tempo without altering the pitch; correct wrong notes; add or modify dynamics. All MIDI events can be changed the way you like it. There are two kinds of sequencers, hardware and software. Hardware sequencers are typically little black boxes dedicated to the task of sequencing. The advantagesof these boxes are they are portable and roadworthy, and less expensive than buying a computer system. Software sequencers are obviously programs you can buy for your computer. Computer monitors can display a larger amount of information than small LEDs or LCDs that are common to hardware sequencers. This makes editing faster and easier. Some other advantages include more memory, more flexibility, customizing to your own style and printing capability. Both hardware and software ware sequencers of all types are similar in purpose, concepts, and features. Computer based sequencing Computer based software sequencing programs have a lot of advantages. But there are a few drawbacks. Porta- bility is one. Unless you already own a computer, cost could be another. If you are not computer literate, there is a steeper learning curve. But, the advantages are considerable. There can be much more information on the screen, making editing faster and easier. Greater flexibility and control over many functions including file management, make this type of sequencing the preferred method. Nevertheless, sequencing a music score is a very long job, everything on the score must be entered, note after note, variations of tempo, volume, etc. Transferring your files to the Web The role of the Internet Service Provider (ISP) Transferring your midi files to the web is not difficult but some rules must be fiollowed. The MIDI system has become common enough that all ISP should support it .However, each ISP has its own settings and send out the webmaster's MIDI files according to some extensions as "audio/midi", audio/x-midi, audio/x-mid, etc. Depending of the extension used, some problems can occur. According to Charles Belov, 90% of problema- tic MIDI files (unplayed on Netscape or Explorer ) turns out to be a faulty extension type being set out by the ISP. I had that problem when my visitors using Netscape could not listen to my MIDI files.
A ISP should use "audio/midi" or "audio/x-midi" settings for the "*.MID" extension, no others.
Any other setting type besides
"audio/midi" and "audio/x-midi" is nonstandard and will cause somebody
(webmeister or web surfer) a problem. Some listeners could be shut out.
Naming your midi files
That's the other major source of error. When naming your files, do not embed spaces in your files names. Otherwise, it is likely to cause problems of recognition by the browsers. It is suggested rather to run the words together or put underscores in place of the spaces.
Copyright François Faucher 1998-2018