Is this St. Ephrem the same one sometimes called "The Melodist"? OR should I go back for more coffee ... :-).
You may be thinking of the same fellow as +Ephraim was the composer of many hymns. Its likely though you are thinking of +Romanos the Melodist, a Syrian who was greatly influenced by the hymns of +Ephraim (who is also called The Syrian, though he was from Mesopotamia).