So far we've been focusing on sound as the main type of data within our DAW.
But there's a separate kind of data that's called MIDI-data which is also
very important in a contemporary music production.
And it, it's important to understand the fundamentals of MIDI if we want to really
work well with a contemporary DAW. Now MIDI is not a direct representation
of sound, like our digital audio is. Instead, it's more like the score that a
musician would read. But instead of a musician reading it
directly, some sort of synthesizer or sampler receives this data.
And performs it or realizes it as audio which we can actually hear.
MIDI stands for Musical Instrument Digital Interface and it's what we call a
serial protocol in that one bit of information is sent at a time.
Now it's being sent very fast, so if we do play a chord, it can sound like it's
chord, but really one bit of information is sent at a time.
And it's important to know what kind of information is sent with each MIDI
message. A MIDI message includes a channel number
and there are 16 possible channels in the MIDI specification.
You can think of it like TV channels. And it would allow me to play a single
keyboard and access 16 different sound sources which would be synthesizers or
samplers. After the channel, the type of message is
sent and there are a variety of different types of MIDI messages.
One of them is a note message, so we can have a note on or a note off message.
you might have noticed on many keyboards there are a bunch of knobs.
Well, most of those send control change messages.
And there's also one special knob that changes the pitch of the synthesizer or
sampler patch, and that's called a pitch bend.
So those are the types of messages. And then there's going to be two data
words. And these gives us the parameters of
those messages. So let's think about a note on a message.
I hold the key down on my keyboard. And it sends a note on message on a
particular channel. Along with that is going to be one data
word that tells us which node it is. Is it middle C is it the C above that.
And then there is another message that sends the velocity.
Now velocity really is how hard you hit the key, we just happen to call it
velocity. But really is just how hard you hit the
key. Now, both data words are 7 bit numbers,
and as we heard earlier, if we want to know how many values there are in a word.
We take 2 to the power of the length of the word, and we get the number.
So, these are 7 bit words, so we get messages from 0 to 127.
And you're going to see those kind of numbers all over the place.
Now a message is sent when you hold down the key.
When I release the key, a second message is sent which is a note off message.
That will also include the channel and the which note it is as a specific
number. And it also includes a velocity which is
a release velocity, how fast you let go of the key.
Now, not all controllers send release velocity.
Many do, kind of the more expensive ones usually.
And not many synthesizer patches, or sampler patches really respond to it.
It'd be tough to come up with a, a parameter of sound that would change with
how fast you release the key. But some synthesizers and sampler do
respond to that. Now it's important to know that two
different messages are sent. Because there are times when you're
working with the DAW or the controller that you find that a note just hangs on
forever. You call it a hungnote.
And that's the instance where the receiving synth had received the note on
message, but didn't receive the note off so it just keeps the note playing.
The solution to that is just to hit all the keys on your keyboard and so it gets
one of those note offs, or use some kind of MIDI panic function.
And panic means to send all notes off which will stop everything from playing.