Abstract This chapter outlines some of the varied relationships between music and philosophy in the Middle Ages. As one of the disciplines of the mathematical quadrivium, musica concerns issues of acoustics but the notation and ontology of music additionally relate to grammar, logic, and rhetoric. Furthermore, music is related to the boundaries between human and non-human animals and overlaps with, while not being completely subsumed by, sonic practices. Medieval music was also implicated in writings on ethics, which give evidence of music’s role in gendered and political identity formation. Finally, the chapter considers what sort of knowledge musical knowledge was in the Middle Ages and why modern thinking might struggle with various aspects of music’s relation to philosophy in this period.