The history of ancient music is one of the most tantalizing subjects in ancient cultural history because we have abundant documentation of its central importance and almost no direct evidence of what it sounded like. Music was everywhere in ancient life — at religious ceremonies, theatrical performances, athletic competitions, private sympotic gatherings, funerals, military operations — and yet the notation system used to record it was lost and has only been partially reconstructed.

Ancient Greek music theory is the best-preserved aspect of the tradition. Pythagoras' mathematical analysis of musical intervals — showing that consonant intervals correspond to simple numerical ratios — was one of the foundational discoveries of ancient mathematics and cosmology. The Pythagorean tradition of the music of the spheres (the idea that planetary orbits produce musical harmonics inaudible to human ears) shaped Western cosmological thought for two millennia.

Fewer than 60 fragments of ancient Greek music survive with notation. The most substantial is the Seikilos epitaph (1st century AD), a complete short song carved on a gravestone. Modern performances of ancient Greek music based on this and other fragments give some sense of the scale intervals and rhythmic patterns, but the timbral quality and performance practice are essentially lost.

Roman musical culture was heavily influenced by Greek precedent and is even more poorly preserved. The hydraulis (water organ), a remarkable Hellenistic invention that used water pressure to maintain stable wind pressure for pipe organs, is the most technically interesting ancient musical instrument and one of the first attempts at a mechanical keyboard instrument.