Here's another scriptural possibility for developing your church's music and worship philosophy:
Let the word of Christ dwell in you richly as you teach and admonish one another with all wisdom, and as you sing psalms, hymns and spiritual songs with gratitude in your hearts to God. (Colossians 3:16)
For years and years I relied on this verse (and its parallel in Ephesians 5:19) as a justification, maybe even a defense, for incorporating a variety of musical styles in the worship services I planned. And I'm pretty sure this is a valid precedent. As best we can tell, “psalms” indicates sort of what we'd think it does – artistic creations directed to God, or in praise of God; anthems or other “presentational” music. “Hymns” seem to have been, even in Paul's day, those well-known and accepted congregational expressions of praise or testimony. Did you know that Philippians 2: 6 – 11 is probably one of the earliest hymns of the Church? And then we've got “spiritual songs,” which appear to be newly composed, fresh and more intimate offerings to God. Modern worship songs, anyone?
Oh, and by the way, the Greek word, “psalmos” indicates a song accompanied by stringed instruments. That's what it was generally understood to mean. Sort of like we'd assume that a symphony is going to be played by an orchestra. Don't let anyone tell you there are no references to instrumental music in the New Testament!
But the real key to all this doesn't lie in the diversity of musical styles we incorporate; how new or how old; how relevant or how traditional. The real key is in that very first phrase:
Let the word of Christ dwell in you richly...
Because without that, our gatherings are just a hodge-podge of influences and expressions and styles and preferences. We can cover that with satellite radio.