code: def midi(self):
          
          result = int(round(12 * log2(self.frequency / 440) + 69))
          if 0 <= result < 128:
              return result
          raise ValueError('%f is outside the MIDI note range' % self.frequency)
docs: Return the (nearest) MIDI note to the tone's frequency. This will be an
          integer number in the range 0 to 127. If the frequency is outside the
          range represented by MIDI notes (which is approximately 8Hz to 12.5KHz)
          :exc:`ValueError` exception will be raised.