void playNote(float randomNote) {
  // plays random note
  
   randomNote = int(randomNote); // convert that number to an int
  
  println(randomNote);
  
  if (randomNote == 1) {
    s_1.play();
    s_1.rewind();
  } 
  else if (randomNote == 2) {
    s_2.play();
    s_2.rewind();
  } 
  else if (randomNote == 3) {
    s_3.play();
    s_3.rewind();
  } 
  else if (randomNote == 4) {
    s_4.play();
    s_4.rewind();
  } 
  else if (randomNote == 5) {
    s_5.play();
    s_5.rewind();
  } 
  else if (randomNote == 6) {
    s_6.play();
    s_6.rewind();
  } 
  else if (randomNote == 7) {
    s_7.play();
    s_7.rewind();
  } 
  else if (randomNote == 8) {
    s_8.play();
    s_8.rewind();
  }
}