It's been awhile since I've read about this issue, but I think the Church Fathers taught that God permitted ancient Israel (ie: first temple Judaism) to use muscial instruments like the harp and lyre and flutes, to help teach the people of God how to worship God. At that time, mankind had not learned how to praise and worship God. The pagans of the time used all sorts of weird and twisted rituals (human and infant sacrifices, wild and erotic dancing, blood letting etc). God taught the Hebrews worship was to be done Liturgically, yet He permitted the use of musical instruments, because humanity was not "ready" for the ultimate expression of heavenly worship on earth. Messiah had not yet come, the Holy Spirit had not been poured out "on all flesh" and so mankind was in a stage or being prepared for the coming of Christ. Even in the Old and New Testament record, we can see a progression of Liturgical worship, to where it became more and more pure and refined. The further back in time you go, the more we get a picture of Israel using instruments, even in the temple. But as we go forward in time, we see less and less of this type of worship. By the time of the New Testament and Second Temple Judaism, we see Liturgical worship had been so refined, that the hours had been added. (the hours of prayer are not written of in the Old Testament that I'm aware of) We also read nothing about intrumental worship in the New Testament record of the 1st Century Jews.
2nd Temple Judaism no longer used instruments except for the purpose of keeping time. (at least not in the Temple) Today in Orthodox Judaism, if you go to a synagogue, they will not use intruments. And this form of Judaism came right out of 2nd Temple Judaism, after the destruction of the Temple, and the exile in 135 AD.
When the Holy Spirit was given on the day of Pentecost, the Church now officially was "not of this world". There is no record of instruments being used in heaven anywhere in the Old or New Testaments. Since Christ's Kingdom, came down to us, and it is the Kigdom of Heaven on earth, we of course do not use intruments, because now worship is to be a mirror of heavenly worship. Ancient Israel was permitted to use insturments, but the New Israel should not.
Here are a few quotes I found on the subject from the Church Fathers, hope this helps some:
Justin Martyr (A.D. 150): "The use of [instrumental] music was not received in the Christian churches, as it was among the Jew, in their infant state, but only the use of plain song. . . . Simply singing is not agreeable to children [the aforementioned Jews], but singing with lifeless instruments and with dancing and clapping is. On this account the use of this kind of instruments and of others agreeable to children is removed from the songs of the churches, and there is left remaining simply singing."
Notice how he wrote the Jews used intruments in their INFANT state. Not neccessarily in the 1st Century, for Israel by that time was already ancient.
Tertullian (c. A.D. 200): "Musical concerts with viol and lute belong to Apollo, to the Muses, to Minerva and Mercury who invented them; ye who are Christians, hate and abhor these things whose very authors themselves must be the object of loathing and aversion."
Eusebius (260-340): "Of old at the time those of the circumcision were worshiping with symbols and types it was not inappropriate to send up hymns to God with the psalterion and kithara . . . But we in an inward manner keep the part of the Jew, according to the saying of the apostle . . . [Romans 2:28f]. We render our hymns with a living psalterion and a living kithara, with spiritual songs. The unison voices of Christians would be more acceptable to God than any musical instrument" (Comments on Psalm 92:2-3).
Chrysostom (345-407): "Just as the Jews are commanded to praise God with all musical instruments so we are commanded to praise him with all our members-the eye, the tongue, ear, the hand. These instruments were then allowed because of the weakness of the people, to train them to love and harmony" (Comments on Psalm 150)
Hope this helps....