Instrumental Music in Worship, Abrogated

"The Psalms are to be sung without the accompaniment of instruments, which are not part of the New Testament pattern of worship. Musical instruments were commanded for use with the offering of sacrifices in the Old Testament temple worship. The death of Christ being the perfect and final sacrifice brought an end to this way of worship. There is neither command for nor example of the use of musical instruments in the words or practice of Christ and the apostles.
The command of the New Testament is to offer the sacrifice of praise—the fruit of our lips."

Reformed Presbyterian Testimony 21.6