'Return a list of all tempos in this score.
If no tempos are found, create a default tempo of 120 qpm.
Returns:
A list of all Tempo objects used in this score.'

def get_tempos(self):

    tempos = []
    if self.parts:
        part = self.parts[0]
        for measure in part.measures:
            for tempo in measure.tempos:
                tempos.append(tempo)
    if (not tempos):
        tempo = Tempo(self._state)
        tempo.qpm = self._state.qpm
        tempo.time_position = 0
        tempos.append(tempo)
    return tempos
