In John 4:23-24, we are told we are to "worship the Father in spirit and in truth: for the Father seeketh such to worship him" (v.23). Furthermore, we are told that we "must worship him in spirit and in truth" (v.24). Notice the elements for proper worship: "spirit" and "truth."  To worship in spirit means that we must have the right attitude in worshipping the Father. God does not want our worship to be vain or insincere. Spiritual worship is that which is done from a pure heart, and in accordance with God's will (this is not to be confused with emotion. Just because worship "feels good" doesn't mean it's spiritual)!  To worship in truth means we must worship in a manner that is pleasing to God, doing only the things which he has prescribed!  If we are to worship in truth, this MUST mean God has provided us THE TRUTH! Why is this important? Because we worship a God of truth (John 17:17), a God whom we can know (John 4:22) and whose commandments we can understand (John 8:31-32).

Scripture is clear about instrumental music in worship to God: IT IS SIN