Since the 1840s, critics have lambasted Wagner for lacking the ability to compose melody. But for him, melody was fundamental – 'music's only form'. This incongruity testifies to the surprising difficulties during the nineteenth century of conceptualizing melody. Despite its indispensable place in opera, contemporary theorists were unable even to agree on a definition for it. In Wagner's Melodies, David Trippett re-examines Wagner's central aesthetic claims, placing the composer's ideas about melody in the context of the scientific discourse of his age: from the emergence of the natural sciences and historical linguistics to sources about music's stimulation of the body and inventions for 'automatic' composition. Interweaving a rich variety of material from the history of science, music theory, music criticism, private correspondence and court reports, Trippett uncovers a new and controversial discourse that placed melody at the apex of artistic self-consciousness and generated problems of urgent dimensions for German music aesthetics.