Easton's Bible Dictionary
(Hebrews menatstseah), the precentor of the Levitical choir or orchestra in the temple, mentioned in the titles of fifty-five psalms, and in Habakkuk 3:19, Revised Version. The first who held this office was Jeduthun (1 Chronicles 16:41), and the office appears to have been hereditary. Heman and Asaph were his two colleagues (2 Chronicles 35:15).
Noah Webster's New International Dictionary of the English Language
(n.) One skilled in the art or science of music; esp., a skilled singer, or performer on a musical instrument.