2 Chronicles 5:11-12

11The priests then withdrew from the Holy Place. All the priests who were there had consecrated themselves, regardless of their divisions. 12All the Levites who were musicians—Asaph, Heman, Jeduthun and their sons and relatives—stood on the east side of the altar, dressed in fine linen and playing cymbals, harps and lyres. They were accompanied by 120 priests sounding trumpets.