MIDI Basics — Beginners Guide

What does MIDI stand for?

MIDI is short for Musical Instrument Digital Interface. It’s a language that allows computers, musical instruments and other hardware to communicate. A MIDI setup includes the interface, the language that MIDI data is transmitted in, and the connections needed to communicate between hardware.

What is a MIDI Keyboard?

A MIDI keyboard is typically a piano-style electronic musical keyboard, often with other buttons, wheels and sliders, used for sending MIDI signals or commands over a USB or MIDI 5-pin cable to other musical devices or computers connected and operating on the same MIDI protocol. The basic MIDI keyboard does not produce sounds by itself, as it lacks an onboard sound engine. Instead, MIDI information on keys or buttons the performer has pressed is sent to a receiving device capable of creating sound through modeling synthesis, sample playback, or an analogue hardware instrument.

What is a MIDI Controller?

A MIDI controller is any hardware or software that generates and transmits Musical Instrument Digital Interface (MIDI) data to electronic or digital MIDI-enabled devices, typically to trigger sounds and control parameters of an electronic music performance. MIDI controllers usually do not create or produce musical sounds by themselves. MIDI controllers typically have some type of interface which the performer presses, strikes, blows or touches. This action generates MIDI data (e.g., on what note was played, for how long, and with which rhythm), which can then be transmitted to a MIDI-compatible sound module or synth using a MIDI cable. The sound module or synth in turn produces a sound which is amplified through a loudspeaker.

What is a MIDI Interface?

A MIDI interface is a device that provides MIDI In/Out to and from a computer or MIDI-equipped hardware via standard 5-pin MIDI jacks. There are standalone MIDI interfaces, virtually all of which connect to a computer via USB. MIDI interfaces can also be integrated into keyboards, pad controllers, control surfaces, and audio interfaces. This provides a wide range of options for configuring your studio or live rig.

What is MIDI Thru?

Short for MIDI Through. The MIDI through is a connection available on many MIDI devices. It’s purpose is to pass on (or through) an exact copy of the data present at the MIDI In of the device. This is distinct from a MIDI out, which can sometimes pass on a copy of the input, but usually has other information on it generated by the device in question. MIDI Thru allows many MIDI devices to have their MIDI connections daisy chained together all being driven by a common source or controller, which makes building complex systems much easier.

What is a Virtual Instrument?

MIDI does not pass audio signal, so if you are using a MIDI controller connected to the computer, you will most likely need some sort of software that will interpret the MIDI and produce sound. This is referred to as a Virtual Instrument or plug-in. If you are using recording/sequencing software, you may already have some virtual instruments included. Virtual instruments can consist of a variety of sounds or can specialize in a particular timbre or category. Whether you’re looking for great piano sounds, epic drum kits, or robotic movement sounds, there is a virtual instrument out there for everyone.

What are the Channel Voice Messages?

The bulk of the musical performance data of a MIDI recording falls into the message category of “Channel Voice Messages”. The 7 Voice Messages are: 
• Note-On
• Note-Off
• Monophonic (Channel) Pressure/Aftertouch
• Polyphonic (Key) Pressure/Aftertouch
• Pitch Bend
• Program Change
• Control Change (or Continuous Controller) messages, a.k.a. CC messages

MIDI Note ON and OFF

The most commonly used MIDI message is a note-on or note-off message. A note-on message is created when pressing a key (or pad), and a note-off message is created upon release. This MIDI note message tells you what note was played, how hard the note was hit, and what MIDI channel the note was played on. Using note-on and note-off messages will determine how long the note took place. All this performance data gets translated to digital information, which can then be read by any other device supporting MIDI.

ON/OFF messages — momentary vs toggle

There are two ways a MIDI note can be sent. When using a keyboard, you will most likely be using momentary messaging. This mean an ON message is created when pressing a key, and an OFF message is created when releasing the key. Sometimes, when using drum pads or buttons, a toggle style functionality may be desirable. When using a toggle setting the OFF messages are not being sent when the pad is released. Instead, the pad will alternate between sending ON and OFF messages when struck.

TIP: Using a button or pad with a toggle function will help control a parameter that needs to stay on after releasing the button/pad. This can be beneficial if you are controlling something like a solo, mute, or an effects ON/OFF switch, which brings us to the next Channel Voice MIDI message: Control Change (CC), but more about this in the next article.

Stay tuned.