Computer Music: Isadora Tutorial Play a Note

Computer Music: Musc 216
Isadora Tutorials: Play a Note (Turn a Note ON/OFF)

In this tutorial you will learn some basic Isadora concepts and then learn how to turn a MIDI note ON and OFF. You should already have studied basic MIDI concepts and know the format of a MIDI Command. In addition, it would be helpful if you have already experimented with the Isadora document, MIDI Commands Demo. Please see MIDI Commands.

The format of the NOTE ON command is:

$90 Key# (0-127) KeyVelociity (0-127)

To send a MIDI COMMAND using Isadora's RAW MIDI DATA actor, you will have to convert all decimal values to HEXADECIMAL. For example:

$90 (the MIDI command STATUS BYTE)
60 (the key MIDDLE C) = $3C
127 (the velocity) = $7F

This TURNS ON Middle C for MIDI Channel 1.

The command for turning a note off is Note ON, KeyVelocity ZER0

For example: $90 $3C $00

STEP 1: CREATE A NEW DOCUMENT

Begin by creating a new document:

STEP 2: ADD THE ACTORS TO PLAY A NOTE

In the top left corner of the NEW DOCUMENT window you will see an area numbered 1 - 9 with circles around each number. This area allows you to select a family or GROUP of actors with similar functions:

Select group #3 (MIDI Group) and then click on the "Send Raw MIDI" Actor toward the bottom of the window. Now move your mouse back over into the middle of the screen. You should see the Send Note ACTOR attached to your cursor. Move your cursor somewhere in the window that seems appropriate and then click the mouse to place the ACTOR in the window:

Now select Actor Group #5 (Mouse & Keyboard):

Click on the Keyboard Watcher Actor and then place it in the window to the LEFT of the Send Raw MIDI Actor:

Drag your mouse around both actors to select them (they turn BLUE in color) and then COPY them (Command+C). Paste new the actors below the current set so that your screen looks like this:

Change the parameters in the ACTOR FIELDS so they match those above:

1. In the "key range" parameter field of both Keyboard Watcher Actors, enter this exactly: 'a' (yes, include the single quotes and yes, it's LOWER CASE). To enter a value, just click in the field and then type.

2. The top Keyboard Watcher DIRECTION should be set to DOWN. To change the field, click in the field and then drag your mouse up or down.

3. The bottom Keyboard Watcher DIRECTION should be set to UP.

4. Connect the Keyboard Watcher Actors to their respective TRIGGER inputs of the Send Raw MIDI actors.

The LOGIC of this configuration goes like this:

- press the 'a' key down and turn on the note #60 (middle c)
- lift the 'a' key and turn off the note #60 (middle c)

Double-click on the TOP Send Raw MIDI Actor to open its parameter window. You should see this:

This contains DEFAULT data which is the MIDI Command to TURN A NOTE ON. Don't change any of this data and click the OK button to close it down. Note that the values here are HEXADECIMAL. If you do not understand about DECIMAL / HEXIDECIMAL conversion, please review this fun tutorial, Hexidecimal Conversion.

Now double-click on the BOTTOM Send Raw MIDI Actor to open its parameter window. You should see exactly the same DEFAULT data as above. But, change the last data byte (7F) to 00. Now the parameter window should look like this:

Click the OK button to close it down.

Although the current version of Isadora has this SEND RAW MIDI DATA fully implemented, it may be preferable for you to use the SEND NOTE actor instead (as demonstrated in class):

To make the connections for playing notes (note on/note off) using the 'a' key, it would look like this:

Although both ways work just fine, the SEND RAW MIDI actor requires HEXADECIMAL values and the SEND NOTE actor requires DECIMAL values. So, you should choose which version works best for you.

STEP 3: Configure SimpleSynth to play notes from Isadora

1. Launch Simple Synth
2. Change the MIDI Source parameter field to: SimpleSynth virtual input

3. Now HIDE the SimpleSynth window by double-clicking in its title bar.

STEP 4: Configure SimpleSynth to play notes from Isadora

You're almost ready to play a note, but first you have to set the MIDI connections in Isadora's MIDI Window.

2. Open Isadora's MIDI Setup Window (under the Windows pull-down menu)
3. Change the DESTINATION Field of Port 1 to SimpleSynth virtual port

Now when you play notes with Isadora, it will play sounds from the SimpleSynth application.

STEP 5: Try it out!

If you have programmed Isadora correctly and have the inputs of SimpleSynth configured, you should hear a note when you play the 'A' key on your computer. In addition, it should turn off when you let up on the 'A' key.

STEP 6: Troubleshooting (debugging)

If you're not hearing any sound when you press the 'a' key, then try this:

1. Is your computer volume turned up?
2. Are you sure your headphones are working?
3. Make sure you have the parameter fields set correctly for all the Actors.
4. Double check the DATA in the Send Raw MIDI actors. The top one should be 90 3C 7F; the bottom one should be 90 3C 00. (You don't have to include the '$' sign.)
5. Make sure you have made the right CONNECTIONS with the actors. The Keyboard Watcher Actors should be connected to the TRIGGER input of the Send Raw MIDI Actors. When you press the 'a' key you should see an 'X' appear in the TRIGGER field. The same thing should happen when you release the 'a' in the NoteOFF set of actors.

5. Perhaps Isadora is unable to make the virtual connection to SimpleSynth. QUIT both programs and then re-launch them. Be sure to SAVE your Isadora file before you QUIT.

6. If you're still not getting any sound, ask for assistance from your instructor.

STEP 7: Save your work

When you complete this tutorial:

1. Save your Isadora file and call it: Project2Controller.YourLastName

2. Save another copy of this file and call it Homework9.YourLastName. See the Class Schedule for specific details about submitting this Homework assignment.

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