telescopic tu-yo, vibrating membranes, The Pipe and OverTone flutes

Premiere: March 1, 2015, Montréal / Nouvelles Musiques 2015: L’air du temps, Hexagram Black Box — Édifice EV — Université Concordia, Montréal (Québec)

∇ (nabla), in mathematics, is a vector differential operator. When applied to a field, it may denote the gradient (direction and magnitude of the greatest rate of increase), the divergence (the field’s tendency to converge toward or repel from a point), or the curl (infinitesimal rotation at a given point). The nabla symbol is also used in logic to indicate indeterminate truth value or vagueness: ∇ (p) means “p has no truth value,” “p is neither true nor false.” The symbol, an inverted delta, takes its name from the Greek word for an ancient Pheonician harp.