The musical universe of the 20th and 21st centuries is a force-field in which styles, instruments, personalities and stories can be found that are ascribable to conceptual frameworks that may differ greatly one from another. Such complexity cannot be traced back to single theories or all-encompassing interpretations, but may be tackled, philosophically, starting from certain characteristics. This book identifies nine such characteristics: namely, Extremes, Noise, Silence, Technology, Audience, Listening, Freedom, Disintegration, and New Media. Each of these permits us to open up unforeseen philosophical-cultural paths and interpret, in its multifarious variety, the developments of contemporary music, profoundly interwoven with the history of thought, culture and society.