2 Chronicles (Author Compiled by Isaiah and Ezra from records of Nathan, Gad, Iddo, Ahijah, Jehu and others.)
30:21And the children of Israel that were present at Jerusalem kept the feast of unleavened bread seven days with great gladness: and the Levites and the priests praised the LORD day by day, singing with loud instruments unto the LORD.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.