By the nymph Argiope, who dwelt on Parnassus, he became the father of Thamyris and Eumolpus. He is closely associated with the worship of Apollo at Delphi, and with the music of the cithara. He is said to have established the chorusses of girls, who, in the Delphian worship of Apollo, sang hymns in which they celebrated the births of Latona, Artemis, and Apollo and some ascribe to him the invention of choral music in general.
The Delphic hymns which were ascribed to him were citharoedic nomes, no doubt in the Doric dialect and it appears that Terpander composed several of his nomes in imitation of them, for Plutarch tells us that some of Terpander's citharoedic nomes were said to have been composed by Philammon, and also that Philammon's Delphian hymns were in lyric measures.
Now Plutarch himself tells us just below, that all the early hymns of the period to which the legend supposes Philammon to belong, were in hexameter verse ; and therefore the latter statement can only be explained by a confusion between the lyric nomes of Terpander and the more ancient nomes ascribed to Philammon.
Pausanias relates that, in the most ancient musical contests at Delphi, the first who conquered was Chrysothemis of Crete, the second was Philammon, and the next after him his son Thamyris: the sort of composition sung in these contests was a hymn to Apollo, which Proclus calls a nome, the invention of which was ascribed to Apollo himself, and the first use of it to Chrysothemis.
A tradition recorded, but with a doubt of its truth, by Pausanias (ii. 37. § 2), made Philammon the author of the Lernaean mysteries.
According to Pherecydes it was Philammon, and not Orpheus, who accompanied the Argonauts.