Instrumental worship for New Testament Christians can be justified

My opponent's first claim is "The meaning of psalm is a song unto God," contesting that a psalm excludes instrument accompaniment. I will need proof of this please to back this claim up. According to Thayer's translation of a Greek-Latin lexicon prepared by Prof. C. L. Wilibald Grimm: "Syn. humnos, psalmos, ode: ode is the generic term; psalm. and humn. are specific, the former designating a song which took its general character from O. T. 'Psalms' (although not restricted to them, see I Cor. 14:15, 26), the latter a song of praise. 'While the leading idea of psalm is a musical accompaniment, and that of hymn praise to God, ode is the general word for a song, whether accompanied or unaccompanied, whether of praise or on any other subject. Thus it was quite possible for the same song to be at once psalmos, humnos, and ode' (Bp. Lightfoot on Col. 3:16). The words occur together in Col. 3:16 and Eph. 5:19." (From page 637.) From this authority it clearly states that the word has not changed in meaning from it's prior Old Testament use. If so, please prove with evidence that I can evaluate and not just claim it changed. ___ Secondly, my opponent argues that 2 Chronicles 29:25 is a proof text that God in the OT allowed singing with instrumental music. Although I agree God did allow singing accompanied by STRINGED instruments in the OT, I see no allowance for anything beyond that. If my opponent wants to prove this he must give a different proof text. 2 Chronicles 29:25 reads: He stationed the Levites in the temple of the LORD with cymbals, harps and lyres in the way prescribed by David and Gad the king's seer and Nathan the prophet; this was commanded by the LORD through his prophets. (NIV) My question is where is there any indication of singing in this text? Also my opponent argues that Psalm 150 sets precedents for instruments that were okay in the OT to use to worship God. I will agree, but where in Psalm 150 does it say those instruments were to be accompanied by the voice? Nowhere. By definition of the word Psalm only allows stringed instruments and by example we only have David accompanying his Psalms with the harp (there might be one with a lyre too, which is basically a guitar). Just because Psalm 150 says instruments such as the "pipe" (NIV) to be praise of God, it only indicates that the music created from the instrument being played by the musician is sufficient enough as praise (without voice accompaniment). Verse 6 reads "Let everything that has breath praise the LORD." While praise could mean singing, praise here does not necessarily mean that. But, even if it did specifically mean sing, where is there any indication to sing with accompaniment the instruments that David just mentioned? Nowhere (other than the stringed instruments because David himself shows by example that Gd accepts his harp in accompaniment to his Psalms as well as by definition of Psalms). ___ My opponent lastly makes an argument that the early NT Church is never recorded as using instruments within their worship. Since a psalm is a psalm whether it has stringed accompaniment or not then to sing a psalm without a stringed instrument would fulfil the command found to sing in Ephesians 5:19. That's not to say that using a stringed instrument would not be allowed, because the word itself by definition allows that. The early church simply did chose not to use instruments because it was their liberty not to. It makes since that if the early church had the liberty to make the choice not to use the instrument that they wouldn't. The early church was constantly being persecuted and instruments would have probably alerted their persecutors if played to loudly. Why would they do that to themselves if they have a choice not too? Also, an argument that says since they didn't use instruments that it means it's wrong to use them is not even valid in the least bit. ___ I would like evidence from my opponent that the term "psalms" in Ephesians 5:19 and Col. 3:16 means "The meaning of psalm is a song unto God," and that by that definition that it excludes instrumental use (stringed). Also, my opponent has dodged tried to dodge the contradiction in his own logic in answering my second question. To recap, my second question was: If you argue that we were only instructed to sing and sing only and that to do anything else while we sing (such as playing an instrument) is sinful, then would you agree that using a song book (reading while you sing) would be adding to the commandment of just sing only? The contradiction in my opponent's logic lies in where he says "You are singing! What is the command? Sing! You are still not doing anything other than what the command includes." If you are using a song book you are singing AND reading, and I find nowhere about reading while you sing in Ephesians 5:19. It is not expedient that you read while you sing, it is just convenient. His logic of excluding an instrument because it is 'adding' to singing would also exclude using songbooks because it is adding reading to singing. This is illogical first because psalms allows instruments to be used and secondly because all logic would go against it.