Ethan the Ezrahite, (firmness) (I Kings 4:31) is credited in the title of Psalm 89. He was one of the musicians appointed by David to officiate in the worship of the tabernacle (I Chronicles 6:44), and his line continued to officiate in the Temple of Solomon. He was of the line of Merari, son of Levi.
Another line of reasoning equates him in I Chronicles 2:6 as the son of Zerah (could be Ezrah), of the tribe of Judah.
Another line of thinking has him being the same as Jeduthun, though that is less authoritative. It was not uncommon, however, for people in the Old Testament to receive new names at their appointment to godly office...