         untztrument.i2xy(i, &x, &y);
         note = LOWNOTE + y * WIDTH + x;
         if(untztrument.justPressed(i)) {
-          usbMIDI.sendNoteOn(note, 127, CHANNEL);
+          noteOn(CHANNEL, note, 127);
           untztrument.setLED(i);
         } else if(untztrument.justReleased(i)) {
-          usbMIDI.sendNoteOff(note, 0, CHANNEL);
+          noteOff(CHANNEL, note, 0);
           untztrument.clrLED(i);
         }
       }

  untztrument.writeDisplay();
}

void loop() {
  unsigned long t = millis();
  if((t - prevReadTime) >= 20L) { // 20ms = min Trellis poll time

#include <Wire.h>
#include <Adafruit_Trellis.h>
#include <Adafruit_UNTZtrument.h>
#include "MIDIUSB.h"

#define LED     13 // Pin for heartbeat LED (shows code is working)
#define CHANNEL 1  // MIDI channel number
