Charles Ellicott Commentary Ezra 3:11

"And they sang one to another in praising and giving thanks unto Jehovah, [saying], For he is good, for his lovingkindness [endureth] for ever toward Israel. And all the people shouted with a great shout, when they praised Jehovah, because the foundation of the house of Jehovah was laid." — Ezra 3:11 (ASV)

They sang together. — They answered each other in chorus, or antiphonally.

Shouted. — As later in religious acclamation.