Musikality Net

In the last post, we talked about audio. Now, we’re going to talk about the brother of audio in writing music: MIDI

MIDI stands for Musical Instrument Digital interface. It is a protocol defined in 1983.

What it is very important to understand, is that MIDI is not sound. Midi represents events. All vst instruments use MIDI and many people are confused, believing that MIDI is actually some kind of a sound generator. MIDI simply transfers information about events like pitch, velocity and duration of a note.

So, for example, when you use a MIDI keyboard to play a vst instrument, and you press C1, the MIDI keyboard, just sends the information that this note has just been pressed.

What is so useful about MIDI is that it is an industry standard protocol that allows all sorts of devices to communicate with each other. Before the advent of MIDI, different devices followed different configurations. Now, it is possible to write something solely on sythesizer, and then transfer it into your DAW to use other sounds you like. Of course you can do the opposite. You can send MIDI messages from your DAW to another source. These messages don’t have to be sounds, they can be triggers for all sorts of events. MIDI cables are usually used in an in-out configuration, but there’s also the midi thru configuration, which tranfers directly the data from the MIDI in to another source, without a delay, something that is usually a problem in larger rigs. You’ll probably never have to deal with this issue as a computer musician .

MIDI was also, once, promoted as means to transfer songs, but with the coming of faster connections on the internet it has lost this function. However, if you search, you can find collections of MIDI songs on the internet, since they still have their uses. You can, for example, open your MIDI file in Cubase and read it like a score, with its score editor, if you are interested in analyzing songs.

In order to maximize compatibility, in 1991, GM (General Midi) was created. This was a protocol that defined, among other things, like polyphony, which program number was which sound. Before that, a synthesizer could use program 1, for example, for a strings sound. With GM, there was a certain spot for each instrument, defining, for example, that program 17 is a drawbar organ. Thus, you could be sure, that a midi song, was played in another synthesizer, with the sounds it was meant to be played.

Now, all the vst instruments use MIDI and they incorporate it in various ways. Drum simulators for example, have "velocity layers", which means, that they read the velocity of the note played and they play a different sample every time. Thus for example, instead of just sampling a snare drum and playing it louder if the velocity is louder, these VSTs trigger a different sample, that was recorded was the snare hit harder, thus producing a more natural sound.

A typical MIDI connection amongst various synthesizers

The most important MIDI parameters you’re going to occupy yourself when you write your music, is velocity (which we refered to above), which defines how loud a note is played. There is also aftertouch, which is extra pressure applied after you press a key and sustain and can be useful is some vst instruments such as Akoustik Piano. Pitch bend can also be used, when you’re trying to emulate a guitar, or play in exotic tunings. Most of the other MIDI commands are used rarely.

When you enter the world of computer music, you have to choose one MIDI-keyboard. Something that you will see concerning MIDI keyboards, is that they have many knobs and faders. One more thing you can use MIDI for, is to "map" (as we say), that is to connect, these faders and knobs, to functions within your DAW. You can connect your faders to the volume faders in your DAW mixer, and your knobs to knobs of your VST instruments, thus controlling every parameter of your DAW from your keyboard. Ableton’s Live, has, probably, the finest MIDI mapping functions. Since it’s role is to be used in live situations, you can map almost every parameter of the program to your MIDI keyboard.

A MIDI keyboard

When you choose a MIDI keyboard, do yourself a favor and buy one with 5 octaves. Don’t be cheap and buy one with two, because you’re going to regret it later, unless, you are TRULY limited in space and money. Furthermore, some keyboards offer weighted keys, which means that the feel of the play resembles that of a piano. They are easier to play if you’re a pianist, but they’re not such a great deal, even if they are generally easier to play than the rest.

When you write using MIDI, you’ll have to be accustomed to the idea of a piano roll. Even if you record everything via a MIDI keyboard, there will be times when you’ll need to edit your work. Piano rolls can be a little tiresome, because you see the notes as in a piano, but in a vertical manner, but this is a discomfort you’ll just have to handle.

A typical piano roll

So, that was it for today! MIDI is very simple, and there are really not many things to know. You just plug a cable and then play However, it won’t hurt you to know a few things about its history and its basic ideas behind its creation. Until next time, just keep playing!

This entry was posted on Monday, January 5th, 2009 at 5:10 pm and is filed under Tutorials. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.