(Κόννος), the son of Metrobius, a player on the cithara, who taught Socrates music. (Plat. Euthyd. pp. 272, c., 295, d., Menex. p. 235e.; Cic. Fam. 9.22.) This Connus is probably the same as the flute-player Connas, mentioned by Aristophanes (Aristoph. Kn. 532), who was, as we learn from the Scholiast, very poor, although he had gained several victories in the Olympic games. Whether the proverb mentioned by Suidas, Κόννον ψῆφον, " good for nothing," refers to the same person, is doubtful.
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