“They were all under the direction of their father in the music in the house of the LORD with cymbals, harps, and lyres for the service of the house of God” (v6). A large portion of Levites were musicians, dedicated to leading the people through songs and prophetic ministry (v1-3). Many “prophesied with the lyre in thanksgiving and praise to the Lord” (v3), meaning that under the power of the Spirit they declared God’s glory and goodness. Far from being disruptive, this was done “under the direction of the king” (v2).
The same Holy Spirit is active when God’s people come together to worship Him, declaring the goodness of God together with “thanksgiving and praise” (v3).