2 Chronicles 5:11-12

11And it came to pass, when the kohanim came out of the Holy Place—for all the kohanim that were present had consecrated themselves, without regard to divisions—

12all the Levite singers—Asaph, Heman, Jeduthun, their sons and their relatives—dressed in fine linen with cymbals, harps and lyres, were standing at the east end of the altar and with them were 120 kohanim blowing trumpets.