Chapter 4 examines the musical activities of Herbert’s elder brothe, Edward, first Lord Herbert of Cherbury (c.1582–1648). Cherbury’s musical activities are regularly overlooked by scholars interested in his work as a philosopher, historian, or diplomat. Yet music played an important role in his self-fashioning as a ‘Citizen of the world’, and these Stoic cosmopolitan ideals shaped his work as a diplomat and as a philosopher. In his philosophical work, Cherbury repeatedly turns to musical ideas to understand the nature of truth as a ‘harmonising’ of our faculties with the world. Most remarkably, evidence suggests that his philosophical ideas influenced his work as a composer: founded on the mathematical and astrological principles of harmony, his lute compositions attempted to express in a deeply personal and private music his relationship to the wider cosmos. The chapter concludes with a discussion of the echo poems composed by both brothers, demonstrating how the musical idea of resonance between the microcosm and the macrocosm informs their poetry.