(Κράτης), a very ancient Greek musician, the disciple of Olympus, to whom some ascribed the composition for the flute, which was called νόμος Πολυκέφαλος, and which was more usually attributed to Olympus himself. (Plut. de Mus. 7, p. 1133e.) Nothing further is known of him.
[P.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890