Peras. Music for Piano together with Apeiron. Music for Large Orchestra (2004/2005), commissioned by Sir Simon Rattle and the Berlin Philharmonic Orchestra (world premiere: 15 June 2005), constitute an entity - the two of them are related as two sides of the same coin.

Work on both compositions was inspired by the contrasting notions known from pre-Socratic philosophy of Peras (the Definite; Order) and Apeiron (the Infinite, the Unlimited). While Apeiron. Music for Large Orchestra seeks to chart the limits (the macrocosmos, so to speak) of orchestral sonority, Peras. Music for Piano penetrates into the structure of the piece and illuminates its microcosmos from inside.

Although both works are audibly related, Peras. Music for Piano soon develops a life of its own and as the piece progresses, it distances itself more and more from its alter ego.