The singing of Psalms was introduced into the public worship of God's people at a set time by His command (1 Chronicles 16:1-8)
“When the ark of God finally rested in the Tabernacle that David had prepared for it, further appointments were made among Levites ‘to commemorate, to thank, and to praise the Lord God of Israel.’ We can be certain that these new functions were not created without divine authority. The same respect to God's appointed ordinances was to be held before the ark in its permanent resting place, as was required in its transportation
It is inconceivable that David, who had just learned the lesson of God's zeal for His worship to be conducted according to His appointed ordinances alone- a lesson that was underscored by the fearful outbreak of divine wrath against Uzzah for transgressing God's commands- would immediately take it upon himself to introduce new offices, and functions among the priesthood without a divine command to do so.
In addition, it becomes clear in this passage that the Lord was introducing through David various changes in the formal worship of His people. The author of The True Psalmody notes, ‘In the worship of the ancient Tabernacle, according to the appointment of Moses, the Israelites were directed to express their joy in God, by blowing with trumpets at the time of offering the sacrifices. But in connection with the offering of sacrifice, David introduced the singing of praise. By his direction the Levites were numbered and distributed into classes, that among other services connected with the worship of the temple, they might ‘stand every morning to thank and praise the Lord, and likewise at evening’ (1 Chronicles 23:30)…And that these regulations in the worship of God and in the service of His temple, were made, not by his own private authority, but by divine direction, we have sufficient evidence.’
Through David, who is identified as a divinely- inspired prophet, God was adding to the ordinances of His worship. In none of these did David act on his own initiative. He was merely carrying out the commands of the Lord. A brief survey of Israel’s history will bear this out…
From the time that the pattern for the Tabernacle was revealed to Moses, through the wilderness wanderings of the Israelites in the desert, and after their entrance into the Promised land, throughout the long period of the Judges, the reign of Saul, and part of David's reign, it is clear that there was no instrumental music in the services of the Tabernacle- God gave no command regarding them. It is not until David begins to make preparations for the Temple construction that we find the first mention of musical instruments being used in the services of worship.” (Comin, 124-125)
