David told the leaders of the Levites to appoint some of their relatives as musicians; they were to play various instruments, including stringed instruments and cymbals, and to sing loudly and joyfully. ¹ 

King Hezekiah and the officials told the Levites to praise the Lord, using the psalms ¹  of David and Asaph the prophet. ²  So they joyfully offered praise and bowed down and worshiped.

as the time when the Jews gave themselves rest from their enemies – the month when their trouble was turned to happiness and their mourning to a holiday. These were to be days of banqueting, happiness, sending gifts to one another, and providing for the poor.