In this paper we introduce the declarative language F for music composition. F supports music composition at a higher level of abstraction than traditional sheet music. Composers are able to express themselves at a high level of abstraction throughout the entire process of composing a piece, and we sketch some of the available transformation of the various component of a composition. F is currently still at a prototype stage (version 0.8), but we hope to evolve the language to be useful in many areas of computer aided music composition and analysis.