Simultaneously with the composition of Répons, Pierre Boulez wrote several short pieces for small ensemble, developing some of the ideas that arose during the gestation of that larger work. Dérive is based on the proliferation of a simple harmonic structure: a series of six permutated chords, each containing the six notes of a cryptogram by William Glock—the work’s dedicatee— and then six transposed chords forming an inverted cryptogram. In this work, resonance plays a central role: the piano holds all the notes of the lowest octave throughout the piece, allowing them to sound more freely, with richer harmonics. Ornamental and melodic figures intertwine in a mood of jubilation until an elided, abrupt end.

Philippe Albèra,

liner notes for the 21 March 1992

performance at the Archipel Festival, Geneva