Just because a piece is notated in 4/4 does not mean that its rhythmic sense is determined solely by duples. What is the term that would apply to the simultaneous presence of two meters within one notated meter?
Is it to simplify coordination that we learn to verticalize beats to be sure that the two hands are together at all times? Isn't it more exciting to take off from there and have one hand play freely while the other keeps the beat?
The idea is not so much to identify a concept as to find the necessity for this multi-layered movement within the body's desire to move the limbs independent of one another and to assert the autonomy of the imagination throughout it all.
A rhythmic concept risks stifling this level of animal vitality.