Hello, this is Dr. Ewell and in this video I will give you more information on MIDI and a MIDI keyboard.

What I have here is my Yamaha MIDI keyboard that I have had for many years. I am showing this to you because it demonstrates how the MIDI instruments work. On your computer—we have talked about this before—you have a card that will play MIDI files. Inside of this instrument here there is a sound generator. We have this keyboard interface the same as you would see on a piano.

What is nice about this keyboard for me is that it has all of the general MIDI instruments listed up here. This is probably too small for you to see on the screen. But you can see a number here that indicates the instrument. In this case we have a 01. I know in General MIDI that is a grand piano. So we have the grand piano sound. You can cycle through getting different sounds. Between 01-08 are the different types of pianos.

Then we come to what are called “pitched percussion” instruments. These are instruments that are often played with mallets on a keyboard arrangement like a xylophone or celeste. Some of these are marimbas, bells, and those sorts of things. Those are different than the percussion instruments we will be studying later.   In any case we have all of the General MIDI instruments.

If I were to go to 57, for instance, there is a trumpet. So I am playing this on the keyboard. This gives me the trumpet notes.

I want to emphasize to you that MIDI is not sound. A MIDI file is a set of commands that will play instruments. This works on software in your computer where the instruments are produced from those sets of commands. This is very different than the wave (.wav) files or the different sound files that you will have in Audacity.

This will be confusing to you because maybe some of you have used Garage Band, which is a program for Mac in which you can have MIDI and sound files together, in the same program, and play. This is one reason I have chosen to have something (software) different. So that you will understand that the MIDI and sound files are not the same. Garage Band does not play on PCs, for this course I needed to find software that worked on everything. So we do our MIDI in Aria Maestosa, which is here. And then you work with your sound files in a different program, which for this course is Audacity.

Now, what I have done is I have loaded in the “Baby Elephant.”  I have it set up to play on measure 56. Let’s hear the ending. OK, so in Aria Maestosa you do not see the computer commands. Instead in Aria Maestosa the MIDI commands are represented in a visual fashion. If we click this one here, they are represented as music notation. A rather strange music notation! Here we have the keyboard representation. I find that this is the simplest for the course. This is guitar representation. This here with the drum is for percussion instruments, non-pitched. And this is sort of a….I don’t know what this is. I guess this is for editing different parameters: volume and other things. Basically we will stick here.

Now what I want you to see is the way that this flute part looks in a program that will show you the computer commands. This is a program called Reaper. Let’s go to the flute. The flute is up on top.  What I have done is I have loaded in the MIDI file. If I click play, nothing happens. Why? Because MIDI is not sound. Reaper, like Audacity, plays sound files. Reaper is another digital audio workstation. We used to use this in the course, but now we are using Audicity because Reaper is no longer free.

OK, so if I select, and move…let’s look at commands here. I am looking at the event list. In Reaper this gives instructions to the computer sound card as to what to play. So first we have the flute is put in channel 1. Notice that each of the melodic instruments have to be in different channels or else if you have the same channel than the PC number needs to rapidly change. You can’t have a flute and clarinet playing in the same channel at the same time because the computer can only generate one type of sound on each channel.

So here we have the PC, program change, for flute and the value is 73. Well that is the General MID number. Let’s see if I can bring it up for you real quickly here. There we go. This is your MIDI chart, which you need to refer to. Unfortunately Reaper is off by one number. So flute should be 74 not 73. So here is the General MIDI number that should be showing in Reaper—74.Then we have other things in here such as volume and the pan position and things like that. And the we get on to the notes.

Let’s go to the end here and I am going to find measure 57. Here we are in Reaper measure 57. If I click on measure 57 in Aria Maestosa, let’s look at the notes. F5, C6, D6, C6 and then we get these two notes. Let’s look at measure 57, F5 C6, D6, and C6. So you can see it happening here. The position tells it where to start in that measure. So this is measure 57, it starts just a little bit later on the first beat. This is the duration, the length of the note, and then it gives the note (pitch). This value here is how loud it is. Notice that is a little bit louder here at the end, 127. 127 is maximum. These are a little bit quieter.

So you can see that every MIDI command is represented in series of numbers of some sort, calling on your computer to play it. Now if we look at these other tracks, for instance, we have strings here. Notice that the strings are on channel 2. Why? Because it is a different instrument with a different sound. We get another instrument here, the brass—channel 3. And so forth.

There are a lot of different channels added for the pitched instruments. Let’s discuss now the percussion instruments. My keyboard has a little button here where it changes over to percussion instruments. It is changing this to MIDI channel 10. In MIDI channel 10 all of the percussion instruments are grouped. They are not grouped by giving them a PC number. In fact, you will just see a PC number of 1 on your keyboard. Instead they are grouped by pitch.

I want to demonstrate for you that if I play this pitch I am getting a certain percussion instrument. If I go higher, go down; as I go up and down each pitch is keyed to a certain percussion instrument. The percussion is always on channel 10; always reserved for channel 10.

You will have the different pitches given here, the different key values—I’m sorry those are actually dynamics here. You will have the different pitches given here or you can also see the key values: refer to that chart. Channel 10, the percussion instruments are at the end. These are the non-pitched instruments. Here you have the different key numbers , which I showed you on the keyboard earlier. This is how you look those up.

So that is your overview of how the keyboard instruments works with MIDI, how the MIDI code is represented in Audacity and also in other programs. Thank you.