This is my assignment on untuned percussion. It’s based on the ideas of phasing and tide tables. The title ‘Welcome to Ceredigion’ was on the tide table for summer 2014 which I drew on for the timing and dynamics. More commentary on the composition process tomorrow. It’s something of an experiment:
The time signature 25/16 relates to 12 and half hours as a close approximation to the time between high tides or between low tides. A half hour is a semiquaver and the shortest unit in the music is a demisemiquaver so that the tides are rounded to the nearest quarter hour. The actual tides follow a more complex rhythm and advance slowly on this period. The turn of the tide is marked by a strike of the claves, and normal ‘clock’ (or earth) time is marked by a wood block every two hours, which corresponds to four semiquavers in the score. This is on the main beat (6×4 + 1)/16 only once every four bars. The perception of the beat shifts accordingly; sometimes I use accents to reinforce the written bar and sometimes to undermine it, for example using a 5 x 5 division of the bar in the bass drum. A whip crash marks the point of the highest ‘spring’ tide about once every 14 days, typically near full moon and new moon when the moon pulls the tides along the same axis as the sun. Over the composition as a whole, there are six such high points when the music is loud and busy. In between these the steady pulse of half hours on the two side drums decays and at the time of greatest slack, disappears altogether. A triangle strike, however, regularly marks the 25th semiquaver.