Register, for organ and orchestra, is one of many collaborations between me and the organist James McVinnie, one of my oldest friends. I’ve always treated the organ as an early version of the synthesizer, with additions and subtractions to the sounds creating sudden shifts of mood, or register. Like in speech, changes in tone and style can be subtle or jarring; here, the organ and orchestra work with and against one another in an animated and intimate conversation, with sudden asides and rapid shifts in tack. The piece is built around three distinct cycles of chords: one, large and ascending, with a sense of slight menace; the second, bright, descending, and brilliant; and the third, a sparkling perpetual-motion machine, in whose genetic past is a Pavane in G minor by Orlando Gibbons (1583–1625), a composer with whose music Jamie and I both enjoy a lifelong romance. Despite the power of the modern organ, the piece ends with a glance towards the Jacobean period, with strings played without vibrato, and the organ in its smallest, most understated register.