Answer
By the time of the New Testament, synagogues had become a common local fixture. This meant the typical worship experience did not include professional temple musicians, and the music became downscaled. Instead of a temple choir, services typically had a single layman cantor. After the destruction of the temple in AD 70, Jews no longer used instruments in the synagogues, in part as a form of mourning and in part as a way of distinguishing themselves from pagan worship practices.
The New Testament mentions instruments in the context of celebrating (Luke 15:25) and mourning (Matthew 9:23) but not for worship in the church or synagogue. The early church more regularly used singing for both praise and training.
Passages
The only instruments specifically mentioned as being played in the New Testament are flutes at Jairus’ daughter’s wake (Matthew 9:23), harps played by the 24 elders before God’s throne (Revelation 5:6) and the tribulation saints (Revelation 15:2), and the trumpets that herald some end-time events, including the rapture (1 Corinthians 15:52). The other references to musical instruments in the New Testament are either metaphors or descriptions of sounds. Metaphors include the uselessness of a harp, pipe, or trumpet that can’t be heard (1 Corinthians 14:7–8) and a comparison of John the Baptist’s asceticism to Jesus’ freedom to eat and drink (Matthew 11:17). Descriptions of musical sounds include a sound from heaven introducing the new song of the 144,000 (Revelation 14:2). At Babylon’s destruction, harpists, pipers, trumpeters, and other musicians will no longer be heard (Revelation 18:22). In the parable of the Prodigal Son, the older son hears music at the celebration for the younger son’s return (Luke 15:25).
The trumpet deserves special mention. Several voices are compared to a trumpet, including God’s at Mt. Sinai (Hebrews 12:19) and the voice that tells the apostle John to write what he sees (Revelation 1:10; 4:1). Even the literal sounding of a trumpet is a symbol for the announcement of an event. In one case, Jesus uses the term to admonish people not to announce when they give to the poor (Matthew 6:2). The other uses are heralding events of the end times, whether the rapture (1 Corinthians 15:52; 1 Thessalonians 4:16), Jesus’ second coming (Matthew 24:31), or the seven trumpets of the tribulation judgment (Revelation 8:2, 6, 13; 9:14). It’s not clear if these are literal trumpets or some other kind of heavenly herald.
References to singing are more commonly literal in the New Testament. Still, there are only two descriptions of people actually singing: Jesus and the disciples at the end of the Last Supper (Matthew 26:30) and Paul and Silas in the Philippian jail (Acts 16:25); Jesus perhaps metaphorically sings in Hebrews 2:12. The other references are mostly instructions to sing (Ephesians 5:19; Colossians 3:16; James 5:13). Paul also metaphorically mentions the Gentiles singing praises to God (Romans 15:9). In the future, the four creatures and the 24 elders (Revelation 5:9) and the 144,000 (Revelation 14:3; 15:3) will sing.
Instruments
Harp: The kithara or cithara is translated “harp” or “lute” (1 Corinthians 14:7; Revelation 14:2; 18:22). A U-shaped bow holds up a crosspiece; some harps have a sound box on the bottom. Strings descend from the crosspiece to the bottom of the bow or box. In secular literature and art, the god Apollo is often presented playing one. A kitharodon is someone who plays a kithara.
Pipe: Aulos is sometimes translated “flute,” but “pipe” is more accurate (Matthew 11:17; 1 Corinthians 14:7; Revelation 18:22). The aulos is similar to a modern oboe—it is double-reeded and played vertically (not horizontally like a flute). Auleton, or aulos-players, often played two pipes at a time.
Trumpet: Salpinx is translated “trumpet” or “bugle.” It was a long, straight, metal pipe with a bell on one end and a bone mouthpiece on the other. The name comes from the word for “reverberate.” It is more of a straight bugle than a trumpet, as it has no valves. Some countries still use “heralds’ trumpets” to provide fanfare for royalty.
Singing
Singing and songs are mentioned in the New Testament more regularly than instruments.
Songs: Most generally, songs (Gr. ode) are sung by the four creatures, the 24 elders, and the 144,000 in Revelation (Revelation 5:9; 14:3; 15:3).
Dirge: Jesus compares His ministry to John the Baptist’s by quoting lyrics from an unknown song in Matthew 11:17. Jesus’ ministry is similar to the sound of cheerful pipes while John’s is like a threneo—a “lament” or “dirge.”
Psalm: To psalleto is to sing psalmos or “songs of praise.” James exhorts believers to sing psalms when feeling joyful (James 5:13). Paul tells the churches to teach and exhort each other with psalms (Ephesians 5:19; Colossians 3:16) as long as the singing is mindful and not chaotic (1 Corinthians 14:15–16).
Hymn: Hymns (Gr. hymnos) are songs that give praise, honor, or thanksgiving to God. Jesus and the disciples sang a hymn at the end of the last supper (Matthew 26:30), and Paul and Silas sang while in the Philippian jail (Acts 16:25). Hymns are mentioned with psalms in Paul’s instruction to exhort other believers with music (Ephesians 5:19; Colossians 3:16).
Instruction
In the days of the early church, hymns acted as a kind of proto-creed. Churches used hymns to teach and remember theology. The New Testament records six such possible hymns:
Ephesians 2:14–16: An explanation that Jesus’ sacrifice reconciled Gentiles and Jews into one church.
Philippians 2:6–11: A description of God the Son’s humility and kenosis when He took on human form.
Colossians 1:15–20: A description of God the Son as the supreme authority and the One who reconciles believers.
1 Timothy 3:16: A synopsis of Jesus’ work that brings us godliness.
Hebrews 1:3: A short summary of God the Son’s relationship to God the Father.
1 Peter 3:18–22: A comparison of Jesus’ death and resurrection and the Christian’s water baptism.
Conclusion
Although musical instruments are not specifically mentioned as being played in a worship setting in the New Testament, neither are they forbidden. In fact, the absence of instruments is identified with great destruction (Revelation 18:22). Singing does take precedence in the New Testament as it is a convenient and effective way to teach and remember the truths related to Jesus’ coming, crucifixion, resurrection, and return. But there’s nothing wrong with using instruments with singing.