The formal study of the history, practice, and theory of music. Musicologists concern themselves with a wide range of topics within music, from biographical research of historical composers to music theory (harmony, rhythm, mode, various forms of notation, etc), to musical instruments and their history and the development of new ones, to the various sciences of acoustics and the human body's capacity to produce and experience music. It crosses over in to history, the performing arts, audiology and medicine, philosophy, physics, and education.