Because instrumental music was directly connected to the temporary aspects of temple worship by divine appointment, instrumental music was part of God’s worship only for a time. Like the rest of the sacrificial system of worship, instruments, along with the Levitical priests who played them, were temporary aspects of worship fulfilled in the New Testament. Just as sacrifices pointed to the sacrifice of Christ, the Levitical instruments were also typical of an aspect of true worship fulfilled in the New Testament worship service.
…Instrumental music was an outward sound symbolically representing the movements of the affections toward God. Now that Christ has come, we have no need of symbolic demonstrations of praise.
Interestingly, the French, Swiss, and Dutch Reformed churches all initially opposed instruments in worship.