def GetLastKey(self, voice=1):
        """key as in musical key, not index"""

        voice_obj = self.GetChild(voice)
        if voice_obj is not None:
            key = BackwardSearch(KeyNode, voice_obj, 1)
            if key is not None:
                return key
            else:
                if hasattr(self, "key"):
                    return self.key
        else:
            if hasattr(self, "key"):
                return self.key
key as in musical key, not index