This chapter on Italian Renaissance philosopher Marsilio Ficino's beliefs regarding the music of the pulse aims to show the extent to which this particular topic functioned as a key concept in his ideas about human physiology and medicine. This chapter outlines the physiological bases for music therapy in Ficino's Timaeus commentary, and then explores how his theoretical ideas about human physiology were used in his musico-therapeutical practice. In addition, he tries to answer the question of how far Ficino's translation and study of the account of human physiology, health and healing in Plato's Timaeus changed the traditional Aristotelian and Galenic views of human physiology, in particular of the relationship between the sense of hearing, blood 'circulation' and the emotions. In his Timaeus commentary Ficino read the passages on humours, health and harmony through the lenses of al- Kindi's astrological thought.Keywords:blood circulation; human physiology; humour; Marsilio Ficino; music of the pulse; music therapy; Renaissance; Timaeus