OBJECTIVE:  In lesson 3 you learned about computer applications and various types of music software environments.  In this lesson we are going to look an application related to computer applications called MIDI, how it has revolutionized the world of music and how it's changing.  In addition, you will learn the basic concepts, terminology and applications of MIDI and its relationship to performing media (voices and instruments) and music software.

Excerpt From Jason Mraz's  I'm Yours

MIDI - Musical Instrument Digital Interface

Is a set of standardized messages that allow keyboards, computers and electronic music devices to communicate with one another.

It can also be used to control other types of electronic devices like lighting systems and special effects systems. 

Was invented in 1983 by a group of electronic instrument manufacturers.

Wouldn't it be great if you could connect several different instruments together and play them simultaneously regardless of which company manufactured the instrument?

-MI=Music Instrument-The controller used to send MIDI into the computer.
-DI=Digital Interface-Digital is referred to as binary code-a series of zeros and ones. 
Example:  00001001011000100100100100100111110001010101101=Middle C!

How MIDI Works

1. MIDI sends performance instructions, data or information.

2.  MIDI is not sound or an audio signal!  You can’t go MIDI out of your keyboard and plug it into a mixer and get sound.

3. When you press a key on your MIDI keyboard you’re not making a sound-you’re sending a performance instruction called a note-on message.

4. The computer translates the signal into music VIA A MIDI Interface and that is what you hear.  The MIDI interface is connected to the computer through a USB or Firewire port.

5. MIDI interfaces are often combined with Digital Audio interfaces creating an Audio/MIDI interface. This is more common among interfaces used in studios.

The rear of a MIDI interface

Audio MIDI/Interface

The rear of an Audio/MIDI Interface


A keyboard controller is a device with piano, organ, or synththesizer-style keys.

Most often has a  selection of knobs, buttons, and sliders. All of these transmit MIDI data to external sound modules (synthesizers), computer software synthesizers, or a hardware or software sequencer.

Most keyboard controllers themselves have no internal sound-generating capabilities.

Act to control the sounds and parameters of other devices.

MIDI Keyboards and some interfaces have 3 MIDI ports:   In-Out-Thru

In>Receives; Out>sends; Thru>Bypasses to another MIDI input on another device-”Daisy-chaining”.

Some keyboards and interfaces only have 2 MIDI ports - In and Out.

MIDI Percussion Controller

Woodwind Controller

Brass Controller

MIDI Guitar Controller

Electric Violin and MIDI Foot Controller

Pitch To MIDI Controller

Converts a monophonic musical line into MIDI data.


Go To MIDI Cables