Music theory is the study of the practices and possibilities of music. The Oxford Companion to Music describes three interrelated uses of the term “music theory”: The first is what is otherwise called “rudiments“, currently taught as the elements of notation, of key signatures, of time signatures, of rhythmic notation, and so on. […] The second is the study of writings about music from ancient times onwards. […] The third is an area of current musicological study that seeks to define processes and general principles in music—a sphere of research that can be distinguished from analysis in that it takes as its starting-point not the individual work or performance but the fundamental materials from…