Bible: Priests Levites Nethinims Porters Singers

Repeated words found across different books in the Bible (KJV):
Ezra 2:70
So the priests, and the Levites, and some of the people, and the singers, and the porters, and the Nethinims, dwelt in their cities, and all Israel in their cities.

Ezra 7:7
And there went up some of the children of Israel, and of the priests, and the Levites, and the singers, and the porters, and the Nethinims, unto Jerusalem, in the seventh year of Artaxerxes the king.

Ezra 7:24
Also we certify you, that touching any of the priests and Levites, singers, porters, Nethinims, or ministers of this house of God, it shall not be lawful to impose toll, tribute, or custom, upon them.

Neh 7:73
So the priests, and the Levites, and the porters, and the singers, and some of the people, and the Nethinims, and all Israel, dwelt in their cities; and when the seventh month came, the children of Israel were in their cities.

Neh 10:28
And the rest of the people, the priests, the Levites, the porters, the singers, the Nethinims, and all they that had separated themselves from the people of the lands unto the law of God, their wives, their sons, and their daughters, every one having knowledge, and having understanding;