Send once [Uno + Sparkfun MIDI Breakout]

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3

I guess I am not sure how to do that. Tomorrow I am going to simplify my code to have just one button until I get this working properly, and then add the other buttons back after I am successful. In the meantime, I have tried creating a variable that will hold the last value recorded by the digitalRead and then use it to compare the states required in the if statements, but I am not quite making the jump in logic necessary. You can see two of my attempts below, marked by comments. I tried a couple of other things but forget what they were exactly but they produced no MIDI message.

void loop(){
  
  // read the state of the pushbutton value:
  stopState = digitalRead(buttonStop);
  goState = digitalRead(buttonGo);
  lastState = digitalRead(buttonLast);
  nextState = digitalRead(buttonNext);
  
  stopwas = stopState;
  gowas = goState;
  lastwas = lastState;
  nextwas = nextState;
  
  // update the debouncer:
  bounceStop.update ( );
  bounceGo.update ( );
  bounceLast.update ( );
  bounceNext.update ( );

  // get the update value:
 int valueStop = bounceStop.read();
 int valueGo = bounceGo.read();
 int valueLast = bounceLast.read();
 int valueNext = bounceNext.read();


  // if a button is pressed, send a MIDI message:
  if (stopwas != stopState) {                                          // here I just tried to succeed by comparing the difference in variables
    MIDI.sendNoteOn(1,127,5);                                       // this MIDI message never fires under these conditions.
    Bounce bounceStop = Bounce(buttonStop,5); 
  } 
  
    if (gowas == LOW && goState == HIGH) {                  // another way of comparing the variables
    MIDI.sendNoteOn(2,127,5);                                      // again, this MIDI message never fires under these conditions.
    Bounce bounceGo = Bounce(buttonGo,5);  
  } 
  
    if (lastwas == LOW && lastState == HIGH) {     
    MIDI.sendNoteOn(3,127,5);  
    Bounce bounceLast = Bounce(buttonLast,5); 
  } 
  
    if (nextwas == LOW && nextState == HIGH) {     
    MIDI.sendNoteOn(4,127,5);
    Bounce bounceNext = Bounce(buttonNext,5);
  } 
 
}

Note: I have changed the title of the thread to 'Send Once' rather than 'Run Once' because, of course, I want the sketch to continue running, but only send the MIDI command once when a button is pushed.