byte commandByte;
byte noteByte;
byte velocityByte;

byte noteOn = 144;

//light up led at pin LED_BUILTIN when receiving noteON message with note = 60

void setup(){
  Serial.begin(31250);
  pinMode(LED_BUILTIN,OUTPUT);
  digitalWrite(LED_BUILTIN,LOW);
}

void checkMIDI(){
  do{
    if (Serial.available()){
      commandByte = Serial.read();//read first byte
      noteByte = Serial.read();//read next byte
      velocityByte = Serial.read();//read final byte
      if (commandByte == noteOn){//if note on message
        //check if note == 60 and velocity > 0
        if (velocityByte > 0){
          digitalWrite(LED_BUILTIN,HIGH);//turn on led
        }
      }
    }
  }
  while (Serial.available() > 2);//when at least three bytes available
}


void loop(){
  checkMIDI();
  delay(100);
  digitalWrite(LED_BUILTIN,LOW);//turn led off
}