One of the main ideas in this book is that music is embedded in discourses and surrounded by ideas that contribute to its meaning. A product of the nineteenth-century German enthusiasm for encyclopaedic knowledge, Guido Adler’s new discipline of Musikwissenschaft (science of music) draws on positivist influences from the social sciences and literary philology, with a view to categorizing and summarizing all existing knowledge about music. In doing so, it divides the study of music into two main areas: historical musicology and systematic musicology, the former concerned with Western art music, the latter turning to acoustics, psychology, sociology, aesthetics and comparative musicology. This chapter discusses the methodologies used by Kerman, Theodor Adorno and Carl Dahlhaus to study the music. By interrogating historical methodology, Dahlhaus challenges traditional attempts to make musical meaning a function of its composer’s biography and develops a healthy wariness of so-called objective historical data.