MIDI Foundations – A Primer to the world of MIDI

MIDI – Foundations

I Figured since MIDI is my specialty as of late I would write my first article here at Audio Geek Zine about it.

MIDI is to some, a great complicated mystery that they may never wrap their minds around completely… but that would be because their minds are feeble. When understood even in the most basic sense MIDI can be harnessed and used to make the impossible possible. I have designed this article to basically get you in touch with the basic concepts of the MIDI universe.

First and foremost, MIDI is an acronym which stands for…

Musical Instrument Digital Interface.

It is a digital information protocol developed in 1983. Being a digital information protocol it basically means that MIDI is only 1’s and 0’s. It is a language that allows communication between musical instruments and related devices that are MIDI Capable (Sequencers, computers, sound modules, samplers, etc.)

MIDI contains NO actual audio information. It is a digital communication protocol which contains only numerical commands.

After awhile many companies became interested in MIDI and its promises of grandeur…. but this in turn created problems, which were remedied through the introduction of General MIDI.

General MIDI

General MIDI is a STANDARD protocol that was implemented in 1993. It is a set of specifications created for the soul purpose of easy communication between all companies MIDI equipment. You might think of it as a sort of universal language of electronic devices.

What is contained in a MIDI signal?

These are the basics of a MIDI signal…

Note ON – tells the device when it should begin the note.

Note NumberIndicates the note which should be played. (Each and every note that can be played by musical instruments has an assigned number)

Note VelocityThis determines the acoustic intensity or volume of the note to be played. This can be a value anywhere from 0 to 127 0 being the quietest and 127 being the loudest.

Note OFFIndicates that the note should stop being played.

This is not the only information included in the signal, but the most important.Additional Information contained in a midi signal includes…Timing information, Pitch Bend, Program Changes, Channel Aftertouch, Polyphonic key pressure, Sustain pedal, Running Status, Etc.

MIDI Channels A MIDI channel is basically used to send each individual part of your MIDI composition to its own individual place in your MIDI network. Without MIDI channels you could write a whole orchestral arrangement and have it placed through one single MIDI module with a piano patch loaded into its memory… to say the least this would not be pretty.*Channel 10 will always be a percussion track*MIDI is capable of 16 channels.

MIDI MODES MIDI modes are the different modes in which a MIDI device may operate, they include…

(MODE 1) OMNI ON – POLYPHONY (MODE 2) OMNI ON – MONO (MODE 3) OMNI OFF – POLYPHONY (MODE 4) OMNI OFF – MONO

What does that mean??!?!

Let me explain…When in Omni Mode, the MIDI device allows the unit to respond to ALL incoming data regardless of its channel.When in Omni off Mode, the MIDI device will respond to incoming data on only ONE specified channel.When Polyphony is engaged, The MIDI device will allow MULTIPLE notes to sound at the same time.When Mono is engaged, The MIDI device will allow only ONE note to sound at a time.

MIDI Ports – What are they and what do they do?

MIDI IN – The MIDI IN port allows for the input of MIDI Data. Or in other words is the RECEIVING port.MIDI OUT – The MIDI OUT port allows for the output of MIDI data. Or in other words is the SENDING port. MIDI THRU – The MIDI THRU port is an entirely different idea though. Simply put, the MIDI THRU port DUPLICATES the MIDI data going into the MIDI IN port and sends it out. I hope you have enjoyed this MIDI Primer lesson.

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