Equivoque is the second piece in an ongoing series of compositions based on J.S.Bach's The Art of the Fugue collectively entitled Spring Equinox, and it was written for the occasion of Bach's 300th birthday in 1985.
Equivoque is a palimpsest of Contrapunctus XII, the first of four two-part canons in the The Art of the Fugue. Basic melodic line, formal structure and tonal evolution are the same in both works, but, whereas Contrapunctus XII is entirely in D minor, Equivoque constantly fluctuates between the original key and that of A-flat minor, tonally the most distant key to D minor. As the title suggests, there is an equivocal treatment of the two tonalities. The two keys are like red and green, image and afterimage; they do not mix, yet they are complementary. There is no linear, "qualitative" modulation from one to the other, but rather a quantitative process of coexistence with various degrees of balance between the opposing tonal forces. One key is pitted against the other and both are struggling for possession of the tonal center. This causes a disturbance to the listener's sense of acoustical perspective, not unlike the kind of disturbance on experiences with some of the engravings and lithographs of M.C.Escher, an artist whose work has considerably influenced my own, particularly in this series of compositions.
It's like two different tonal colors splashing together to form a third atonal color, each time pushing any kind of tonal focus just beyond the listener's grasp. Quite an innovative concept that literally snapped me to attention as soon as I heard it. I only wish I had thought of this idea first.
