Janus
Janus-faced
Two faced, facing two ways.
See Also
Duality
double-game
Janus-faced center
mate-pairs
Ramsay - How the Diatonic Germ becomes a 4-Note Chord
Ramsay - The Two D's - The Rah and the Ray
Ramsay - The Outlook of the Janus-faced D
Reciprocal
Sex
11.22 - Reciprocality of Dimensions and Music Intervals