The Sonata for Two Pianos and Percussion is a musical composition by the Hungarian composer Béla Bartók. It was written for a very unusual combination of players. Four players are needed to perform this sonata: two pianists and two percussion players. The two pianists each have a piano, and the two percussion players play seven instruments between them: three timpani, xylophone, one side drum with snares and one without, a suspended cymbal, a pair of cymbals, a bass drum, a triangle and a tam-tam.