Notions of decadence, decline, and decay are intrinsically linked to the history of art. The discipline’s three recognized forefathers ? Giorgio Vasari, Johann Joachim Winckelmann, and Heinrich Wölfflin ? all relied on the concept of decadence (and its antonym, progress) to make sense of the history of the visual arts and to evaluate the art of their times. A developmental model of art was central to the interpretative schemes of these art historians. In this organicist model, earlier developments prepare the stage for what comes later; and after a particular style flourishes for a time, its decline is inevitable as newer styles overtake it. Decadent artists such as Gustave Moreau and Aubrey Beardsley mock aesthetic standards and moral rules, precluding universal appreciation, and proudly so. Decadent artists and decadent audiences are estranged from their society and feel disdain for those who are scandalized by decadent art’s innovative form and immoral subject matter.

The idea of decadent music may be as old as music itself, dating back at least to classical antiquity. This chapter offers a history of the concept from the classical period through the Middle Ages, the Renaissance, and the eighteenth century, before concentrating on the explosion of the idea across Europe from the mid-nineteenth century onwards. Classical writings often invoke a model of music that can be understood as proto-decadent ? for which read morally ‘bad’, formally flawed, hyper-affective, enervating, or corrupting in some way ? even if the term itself is not used. Then, as later, decadent music was perceived and defined by its effect on its listeners or by its formal properties, as Nietzsche understood Wagnerian opera in the nineteenth century. Music, it seems, has always been understood to contain the potential to disrupt and contaminate itself and its audience, requiring aesthetic, social, even state control ? control articulated via the idea of decadence.