Strabo Geography 14. 643 :

[on Colophon]: According to Pindar, Polymnastus was one of the famous musicians; for he says: “Thou knowest the world-wide saying of Polymnastus the man of Colophon.” 28

Plutarch On Music 3 :

What was done in the lyric sphere by Terpander was done in that of the flute by Clonas, the first composer of flute-sung nomes and of processional songs: he used elegiac and epic verse. His successor Polymnastus of Colophon followed his example. The nomes of these flute-poets, my excellent Onesicrates, were sung to the flute, and Lament, the Comarchius or Rout-Leader’s, the Schoenion or Rope-Song, the Cepion or Garden-Song, the Dirge, and the Three-part. To these were added afterwards the Polymnastian Songs, as they are called.

Ibid. 5 :

The successor of Terpander and Clonas is given as Archilochus. But some historians make out that Ardalus of Troezen composed music for flute and voice before the time of Clonas, and that the poet Polymnastus son of Meles of Colophon flourished before his day and composed the Polymnastian nome. The claim of Clonas to be the author of the Special nome and the Rope-Song is borne out by the compilers of the registers, and Polymnastus is mentioned by two of the lyric poets, Pindar and Alcman.

Pausanias Description of Greece 1. 14. 4 :

The Thales who stayed the plague at Sparta . . . according to Polymnastus of Colophon, who composed some epic lines upon him for the Spartans, was a native of Gortyn.

Plutarch On Music 8 :

There were three modes employed by Polymnastus and Sacadas, the Dorian, the Phrygian, and the Lydian . . .

Ibid. 9 :

The first establishment of music at Sparta was due to Terpander. The second is best ascribed to Thaletas of Gortyn, Xenodamus of Cythera, Xenocritus of Locri, Polymnastus of Colophon, and Sacadas of Argos. For we are told that the institution of the Feast of Naked Youths at Sparta, of the Provings in Arcadia, and of the Feast of Garments as it is called at Argos, was due to these musicians. Thaletas, Xenodamus, and Xenocritus were composers of Paeans, Polymnastus of the so-called Orthian or High-pitched Songs, and Sacadas of Elegies . . . Polymnastus, too, composed nomes to be sung to the flute. But whether, as the writers on the theory of music aver, he employed his musical powers upon the Orthian, in the absence of ancient testimony we cannot tell for certain.

Ibid. 29 :

Polymnastus is credited with the invention of what is now called the Hypolydian mode, and is said to have greatly increased the three-quarter-tone lowering, and five-quarter-tone raising, of notes in the scale.29

Aristophanes Knights 1281 :

. . . That scoundrel Ariphrades . . . and doing, not singing, the “Polymnestian” and consorting with Oeonichus. Now whoever is not utterly disgusted by such a man as this, shall never drink out of the same cup as I.30

Hesychius Glossary :

To sing the Polymnestian: This was a kind of musical piece. Polymnestus was a lyric poet of Colophon, of a very merry type.

Suidas Lexicon :

Polymnestus: . . . the Polymnestian are songs of Polymnestus who, like the above, is satirised for his obscenity. Compare Cratinus: “And learns music and sings the Polymnestian songs.”

28. Pind. fr. 188
29. the reading is doubtful, but cf. Mus. Script. Gr. Janus pp. 301, 302 (= Baccheius 41, 42) where these are said to be features peculiar to the Euharmonic scale.
30. cf. Sch. Luc. p. 235 Jacobitz