Tonal progression in Bartók's 'Etudes', Op. 18

Abstract

Bartók's mature musical language was born of both folk and art-music sources which influenced the composer in equal measure. The Three Studies for piano, Op. 18, represent a significant step in the evolution of the composers synthesis of the art-music source. All three etudes are based on equal-interval chains called interval cycles. Each of the three etudes represents a stage in the process of intervallic augmentation the composer named diatonic expansion. This concept, together with that of chromatic compression, is fundamental to all his mature works. The first etude expands the chromatic scale to two whole-tone scales. In the second etude the intervals are expanded to include the minor and major thirds as well as the perfect fourth, while in the third etude the tritone becomes the final step in the expansion process. The interactions of the ever-expanding interval cycles generate an array of diatonic, non-diatonic and abstract pitch collections. Parts of the opus rely on the concept of tonal progression based on axes of symmetry, which reached its perfection in later works such as the Out of Doors Suite and Music for Strings, Percussion and Celesta.