1 Chronicles 25:28

The one and twentieth to Hothir, he, his sons, and his brethren, were twelve:

The verse names the twenty-first lot among the twenty-four courses of temple musicians, the course assigned to Hothir. That course totaled twelve persons in all, Hothir himself together with his sons and his brethren. Each of the courses was likewise composed of twelve men who had been especially instructed and made skillful in the use of musical instruments.

These organized courses belonged to the larger company of four thousand who praised the Lord with instruments. David established this arrangement at the time Solomon was placed upon the throne. It was part of his careful apportioning of special duties to the men best fitted for them, and of his perfecting of the organization of the priests and Levites, the civil officers, and the army.