The following is the results of your search for courses.
Courses: When David was not permitted to build the temple, he proceeded, among
the last acts of his life, with the assistance of Zadok and
Ahimelech, to organize the priestly and musical services to be
conducted in the house of God.
1. He divided the priests into twenty-four courses
(1 Chronicles 24:1-19)
sixteen being of the house of Eleazar and eight of that of
Ithamar. Each course was under a head or chief, and ministered
for a week, the order being determined by lot.
2. The rest of the 38,000 Levites
(1 Chronicles 23:4) were divided also into
twenty-four courses, each to render some allotted service in
public worship: 4,000 in twenty-four courses were set apart as
singers and musicians under separate leaders
(1 Chronicles 25:1-31).
4,000 as porters or keepers of the doors and gates of the
sanctuary
(1 Chronicles 26:1-19) and 6,000 as officers and judges to see
to the administration of the law in all civil and ecclesiastical
matters
(1 Chronicles 26:20-32). This arrangement was re-established by
Hezekiah
(2 Chronicles 31:2) and afterwards the four sacerdotal courses
which are said to have returned from the Captivity were
re-divided into the original number of twenty-four by Ezra