A chord may be subjected to 4 possible metamorphoses which may change
     its direction,
     its position in the series of fifths (measured in chord FRAMEs), and
     its interior or exterior position with respect to the two swings.
Some of its orbits may change note,
     and two of its notes may exchange orbits.

Metamorphoses 1 and 4 are the most useful.
Metamorphosis 1 (on each chord) for producing the "Circle", and
Metamorphosis 4 for changing, say, the chord of IV⁶ into the chord of II⁷.

Open or Closed
Metamorphoses may be presented
     either open, where both forms are heard, one after the other,
          and the changes perceived,
     or closed, where only one form is heard, the first or the last,
          and the changes are not perceived.