“To celebrate the 125th anniversary of Béla Bartók’s birth,” the composer writes, “I have composed a piano concerto in which I have developed a few of Bartók’s ideas and ways of thinking, in particular his fondness for parallel runs in octaves, sixths, or other intervals found in his piano concertos. My piano concerto CAP-KO [Concerto for Acoustic Piano, Keyboard, and Orchestra] for acoustic and digital piano incorporates a piano technology of the future by which a computer automatically creates and adds intervals in parallel with the notes played by the soloist. Based on this initial piano concerto, I have developed two further versions of the piece. Sonata per sei is written for a chamber music formation of two pianos, a sampler-keyboard, and three percussionists. The third version, Concerto for Two Pianos, is composed in traditional concerto form for two acoustic concert pianos and orchestra.”

Sonata per sei had its premiere at the International Bartók Festival in July 2006. It is cast in five movements that seem almost continuous, as ideas and textures evolve organically, and the parallelism Eötvös mentions is much apparent throughout. The first movement begins with three snare drums treated polyphonically, and the second is mainly a Bartókian toccata for the two pianos, including a short cadenza. The third adopts a more chordal approach in its framing sections, around a skittish center that fractures the chords into component intervals. The fourth movement, subtitled “Bartók crosses the ocean,” suggests some of Bartók’s night music over the crashing waves of an ocean drum (a double-headed frame drum with metal pellets inside). The finale gathers ideas from the previous movements into a volatile summation, with an emphasis again on the pianos and toccata bravura.