1 Chronicles 25:7

So the number of them, with their brethren that were instructed in the songs of the Lord, the leaders among the musicians in the king's Tabernacle and in that at Gibeon, even all that were cunning, was two hundred four-score and eight. There were thus twenty-four classes, or choirs, of twelve musicians each, one class of skilful and experienced leaders being engaged for a week at a time, and having charge, in rotation, of those of the four thousand singer who were then on duty. Songs of praise, skillfully rendered in honor of the Lord, are a delight to Him, especially if the work is done systematically and in harmony.