The extent of music's penetration across the arts can be gauged from the fact that music is the touchstone for all aesthetic experience. The first half of the nineteenth century saw the birth of the concept of autonomy, besides the idea of absolute music. The disenchantment following the failure of the 1848 revolutions across Europe, and the general retreat of the arts from social engagement into the inwardness which had characterised the German Romantic aesthetic from the earlier part of the century, sowed, in the period of late Romanticism, the seeds of modernism and the avant-garde. Arthur Schopenhauer is probably, next to Friedrich Nietzsche, the most influential philosopher of the second half of the century. For Schopenhauer the power of art is the joining of the sensuous particular and the world of universal Ideas. The chapter also discusses the consideration of Nietzsche's position regarding the relation between form and expression after an examination of Eduard Hanslick's concept of form.