'Finds the major key that this melody most likely belongs to.
If multiple keys match equally, the key with the lowest index is returned,
where the indexes of the keys are C Major = 0 through B Major = 11.
Returns:
An int for the most likely key (C Major = 0 through B Major = 11)'

def get_major_key(self):

    key_histogram = self.get_major_key_histogram()
    return key_histogram.argmax()
