Point Counter Point
From the Encyclopaedia Britannica, 11th Edition, 1911:
COUNTERPOINT (Lat. contrapunctus, “point counter point,” “note against note”)
“In music, the art happily defined by Sir Frederick Gore Ouseley as that ‘of combining’ melodies….
Double Counterpoint is a combination of melodies so designed that either can be taken above or below the other. When this change of position is effected by merely altering the OCTAVE (from Lat. octavus, eighth, octo, eight) of either or both melodies (with or without transposition of the whole combination to another KEY), the artistic value of the device is simply that of the raising of the lower melody to the surface. The harmonic scheme remains the same, except in so far as some of the chords are not in their fundamental position, while others, not originally fundamental, have become so. But double counterpoint may be in other intervals than the octave; that is to say, while one of the parts remains stationary, the other may be transposed above or below it by some interval other than an octave, thus producing an entirely different set of harmonies.”
biography of Aldous Huxley
and the entry below.
Related material:
A Contrapuntal Theme.