Census and Classification of the Levites

1 Chronicles 23:3-5

A census of L'vi'im thirty years old and over was taken, and their number came to 38,000.

Of these, 24,000 were to oversee the work on the house of ADONAI, while 6,000 were officials and judges

4,000 were gatekeepers, and 4,000 sang praise to ADONAI "with the instruments I made for the purpose of singing praise."