I wanted the character of this piece to be a precarious one, continually on edge and not giving predictable paths through to the end. The title CUSP refers to this.
Harmonically I wanted the piece to shift through different modes and tonality. Rhythmically I wanted simple phrases to alternate with those of more subtlety. I wanted the personality to be capable of changing abruptly in almost schizoid fashion but I wanted to retain the choice to occasionally not do these things.
The piece proceeds by juxtaposing three distinct themes. These are differentiated as just described and also by tempo modulation. Each theme develops in its own way so that when it recurs a new facet may have been incorporated. For instance the first theme, at its first showing, barely moves out of the range of the throat notes and the implied modality therein, but at its next recurrence the notes D in the clarion register and B in the chalumeau register appearing at bar 59 expand the range and also shift the harmony to G major momentarily. The third theme, on the other hand first seen at bar 53, at each reappearance is given a reduced duration to work within and only on its fourth showing is expanded back out as the climax of the piece. The second theme when it first appears at bar 23 repeats a simple and unsophisticated rhythmic phrase, however as the piece progresses increased syncopation and a tendency toward harmonic pacing produce more of a fluid groove. And so in contrast to the abrupt shifts which pervade the rest of the piece, I wanted the end to stabilise then die away thereby maintaining unpredictability.
The piece was commissioned by Andrew Roberts and composed in January 1997. It was written specifically for the French national clarinet competition - Le Trophee de Paris.