@classmethod
def _fill_single_double_repeats(cls, measures):
    """Replaces one- and two-measure repeat symbols with the appropriate chords
        :param measures: A list of measures (as strings)
        :return: A list of measures with filled repeats
        """
    for i in range(1, len(measures)):
        if measures[i] == 'x':
            measures[i] = cls._remove_markers(measures[i - 1])
    for i in range(2, len(measures) - 1):
        if measures[i] == 'r':
            measures[i] = cls._remove_markers(measures[i - 2])
            measures[i + 1] = cls._remove_markers(measures[i - 1])
    return measures
