There is a big difference between writing for a given set of instruments and writing for people you know. When I know the instrumentalists, I get a different kind of inspiration when the music is conceived. This was the case with Cotidales, where in different moments throughout the piece one or two instruments become more prominent, as if coming to the foreground while the others follow or remain silent or in the background. The whole process becomes like a play with characters that interact with each other.

Cotidales has four very distinctive sections where the whole ensemble plays. The introduction is one of these, which develops out of natural harmonics. This is followed by a second more playful section. Other shorter sections serve as transitions and are characterized by having one or two instruments in the foreground. The cello and piano are featuring in the first transition that leads to the third section, built mostly on slow glissandos in the strings interspersed by the piano’s interjections. Another short transition given to the second violin and viola introduce the tremolando material which characterizes the fourth section. A cadenza like passage is given to the piano that grows out of the fourth section. The last ‘transition’ functions mostly as a coda. Led by the piano the first violin features at the end of the work that, as in the piano cadenza, some ideas previously heard, come back in a different light.

In the language of mariners, the words co-tidal line are used to indicate on a map the geometrical points at which a tidal level (specially high tide) occur simultaneously. This word seemed appropriate, not only because it serves as a metaphor for those moments at which two or more instruments coincide, but also because the Melbourne Festival commissioned the piece. Many tidal levels across many seas away from London, where I wrote most of the piece.

While I was still writing the last bars, across the other side of the world my dear Grandmother left this world. It is to her memory that this work is dedicated.