def from_progression_shorthand(self, shorthand, key='C'):
        """Empty the container and add the notes described in the progressions
        shorthand (eg. 'IIm6', 'V7', etc).

        See mingus.core.progressions for all the recognized format.

        Example:
        >>> NoteContainer().from_progression_shorthand('VI')
        ['A-4', 'C-5', 'E-5']
        """
        self.empty()
        chords = progressions.to_chords(shorthand, key)
        # warning Throw error, not a valid shorthand

        if chords == []:
            return False
        notes = chords[0]
        self.add_notes(notes)
        return self
Empty the container and add the notes described in the progressions
        shorthand (eg. 'IIm6', 'V7', etc).

        See mingus.core.progressions for all the recognized format.

        Example:
        >>> NoteContainer().from_progression_shorthand('VI')
        ['A-4', 'C-5', 'E-5']