The Delphic Hymns to Apollo are two paeans in honour of the god, inscribed on the wall of the Athenian Treasury at the sanctuary of Delphi and dating to the later second century BCE. They are of exceptional importance because the inscriptions preserve, above the words, marks of musical notation, making them the earliest substantially complete pieces of Greek music to survive; from them scholars have reconstructed something of how the melodies sounded. Composed for performance at Delphi, very likely at a festival procession of Athenians honouring Apollo, the hymns recount the god's coming to Delphi and his defeat of the serpent that guarded the oracle, and call upon him and the Muses. As both religious texts and musical documents they are a unique survival, joining the worship of Apollo at his most famous oracular shrine to the actual sound of the music that accompanied it, and they remain a cornerstone of the study of ancient Greek music.
The notation, a system of letters and signs placed above the sung syllables, lets modern scholars work out not just the words but the actual pitches of the melody, something almost never possible for Greek religious music, since most texts survive without any trace of how they sounded. The hymns are usually linked to a delegation sent by Athens, and their discovery in the nineteenth century, carved into the Treasury wall where visitors to the sanctuary would have seen them, gave scholars their first real evidence for how ancient Greek vocal melody actually moved, reshaping the study of ancient music.