The Bible shows very plainly that the use of musical instruments is proper when praising God.
We read in Psalm 150:3-4: "Praise Him with the sound of the trumpet; praise Him with the lute and harp! Praise Him with the timbrel and dance; praise Him with stringed instruments and flutes! Praise Him with loud cymbals; praise Him with high sounding cymbals!" In the days of King Hezekiah, the king "stationed the Levites in the house of the LORD with cymbals, with stringed instruments, and with harps, . . . for thus was the commandment of the LORD by His prophets. The Levites stood with the instruments of David, and the priests with the trumpets. . . . So all the congregation worshipped, the singers sang, and the trumpeters sounded . . ." (II Chronicles 29:25-26, 28).
Some claim that the teachings in the Old Testament do not apply to the church today. However, that argument is false! Jesus Himself says that man ought to live by every word of God (Matthew 4:4) and that the entire Old Testament is God's Word (Luke 24:44). Paul writes that the Scriptures (referring to the Old Testament) are "profitable for doctrine, for reproof, for correction, for instruction in righteousness" (II Timothy 3:15-17).
Furthermore, the New Testament itself reveals that God is praised in heaven with instrumental music (Revelation 5:8; 14:2-3). Revelation 15:2-3 tells us that the resurrected saints will praise God to the accompaniment of harps.
These and other scriptures prove it is perfectly proper to praise God by singing to the accompaniment of musical instruments or by musical instruments alone.