The overseer of the Levites in Jerusalem was Uzzi the son of Bani, son of Hashabiah, son of Mattaniah, son of Mica, of the sons of Asaph, the singers, over the work of the house of God.
Having given an account of the principal persons that dwelt in Jerusalem (a larger account of whom he had before, Ch1 9:2, etc.), Nehemiah, in these verses, gives us some account of the other cities, in which dwelt the residue of Israel, Neh 11:20. It was requisite that Jerusalem should be replenished, yet not so as to drain the country.
Commenting on Nehemiah 11:20-36
THEIR NAMES. (Neh. 11:3-36) the chief of the province--that is, Judea. Nehemiah speaks of it, as it then was, a small appendix of the Persian empire. in the cities of Judah dwelt every one in his possession in their cities--The returned exiles, who had come from Babylon, repaired generally, and by a natural impulse, to the lands and cities throughout the country which had been anciently assigned them.
Commenting on Nehemiah 11:3-36
the sons of Asaph, the singers were over the business of the house of God--They were selected to take charge of providing those things which were required for the interior of the temple and its service, while to others was committed the care of the "outward business of the house of God" (Neh 11:16).