In the New Testament God is specific on the kind of music He wants in worship.
“…. sing and make melody with your heart to the Lord” (Ephesians 5:19).
“… admonishing one another with psalms and hymns and spiritual songs, singing with grace in our hearts unto God” (Colossians 3:16).
There is no mention or authorization for instrumental music. Singing, unaccompanied vocal music is authorized by God. It is safe and unquestioned. We are warned that to go beyond the doctrine of Christ in anything is to be without God. (2 John 9).
You will not find a mechanical instrument of music used in worship to God. The reason for such is that God has been very plain in saying that we are to sing (Colossians 3:16, Ephesians 5:19). Since we have such love for Christ and His commands, we would not presume to add that which He has not authorized in worship to Him. After all, it was He who said our worship must be “in spirit and in truth” (John 4:23-24).
IS IT IMPORTANT?
The matter of music in worship is a minor and insignificant practice to many people. But when we remember the unacceptable worship given by Cain because he brought the wrong kind of offering, and the terrible death of Nadab and Abihu because they offered a strange fire on the altar… we see God’s attitude toward additions or changes. Further we are warned that to go beyond the doctrine of Christ in anything is to be without God (2 John 9).