Nehemiah 12:45
And they kept the watch of their God, and were responsible for making things clean, and so did the music-makers and the door-keepers, as it was ordered by David and Solomon his son.
1 Chronicles 25:1-26
Further, David and the chiefs of the servants of the holy place made selection of certain of the sons of Asaph and of Heman and of Jeduthun for the work of prophets, to make melody with corded instruments and brass; and the number of the men for the work they had to do was:
1 Chronicles 23:28
Their place was by the side of the sons of Aaron in all the work of the house of the Lord, in the open spaces and in the rooms, in the making clean of all the holy things, in doing all the work of the house of the Lord,
2 Chronicles 23:6
But let no one come into the house of the Lord but only the priests and those of the Levites who have work to do there; they may go in for they are holy; but the rest of the people are to keep the orders of the Lord.