Now in his mid-40s, Sam Hayden certainly doesn't go out of his way to win friends and influence people with his music. Many of his works seem at first encounter uncompromising and rebarbative, and stylistically seem more closely connected with the complexity of composers such as Brian Ferneyhough than with the music of Hayden's teachers Jonathan Harvey and Louis Andriessen. But though the two pieces that open this collection from the last decade seem to be the opposite sides of that same, rather forbidding coin – System/Error assembles three virtuoso instrumental lines, for violin, flutes and percussion into a lightning-fast mosaic; Presence/Absence melds a disparate quintet into a slowly changing continuum – what makes them anything but forbidding is the energy and exuberance that powers so much of Hayden's invention.  Misguided is more frieze-like – six short movements that themselves are made up of self-contained musical objects – while Die Modularitäten presents a seven-piece ensemble with an array of discursive ideas, ranging from duets to passages for the full group, and often involving electronic sounds, too. They and the conductor then have to organise these elements into the finished 20-minute work.