Name noteOn ( )
Examples
import promidi.*;

MidiIO midiIO;

void setup(){
  size(128*5,128*5);
  smooth();
  background(0);
  
  midiIO = MidiIO.getInstance(this);
  println("printPorts of midiIO");
  midiIO.printPorts();
  midiIO.openInput(0);
}

void draw(){

}

void noteOn(Note note){
  int vel = note.getVelocity();
  int pit = note.getPitch();
  
  fill(255,vel*2,pit*2,vel*2);
  stroke(255,vel);
  ellipse(vel*5,pit*5,30,30);
}

void noteOff(Note note){
  int pit = note.getPitch();
  
  fill(255,pit*2,pit*2,pit*2);
  stroke(255,pit);
  ellipse(pit*5,pit*5,30,30);
}

void controllerIn(Controller controller){
  int num = controller.getNumber();
  int val = controller.getValue();
  
  fill(255,num*2,val*2,num*2);
  stroke(255,num);
  ellipse(num*5,val*5,30,30);
}

void programChange(ProgramChange programChange){
  int num = programChange.getNumber();
  
  fill(255,num*2,num*2,num*2);
  stroke(255,num);
  ellipse(num*5,num*5,30,30);
}

Description The noteOn() function is called everytime a note on command comes through one of your opened midi inputs.
Syntax
noteOn(note);
Parameters
note   Note, of the incoming note on
Returns None
Usage Web & Application
Related Note
noteOff ( )
controllerIn ( )
programChange ( )