Charles Ellicott Commentary 2 Chronicles 34:12

"And the men did the work faithfully: and the overseers of them were Jahath and Obadiah, the Levites, of the sons of Merari; and Zechariah and Meshullam, of the sons of the Kohathites, to set it forward; and [others of] the Levites, all that were skilful with instruments of music." — 2 Chronicles 34:12 (ASV)

And the men did the work faithfully. — Literally, And the men were working (or dealing) in good faith in the work. In 2 Kings 22:7 Josiah instructs the High Priest not to require any account of the money delivered to the master-workmen, because they work in good faith.

And the overseers of them were. — And over them were set. The names of the overseers, and the details added in the next verse, are peculiar to and characteristic of the chronicler.

To set it forward. — To lead, conduct, preside; usually a musical term. (Compare to 1 Chronicles 23:4).

And other ... music. — Literally, and the Levites, namely, every one skilled in the instruments of song. (Compare to 1 Chronicles 15:16; 1 Chronicles 25:7).