So what DOES Biblical music look like?

One can not be certain, really.  On one hand, you have the harp/lyre, consistent with slower, contemplative music.  You have the trumpet, suitable for loud or martial music.  You have the timbrel/tambourine, drums, suitable for martial, percussive, and celebratory music.  You have singers and, to an extent ( see Psalms 149 and 150), dancers.

In other words, absent modern instruments like the pianoforte, bass guitar, and such, we have the ingredients to do just about any of today's genre.  We might assume that it would follow classical Mediterranean or Jewish patterns.  Assuming the latter, we have the issue of whether it would be like Haifetz, klezmer, or perhaps the Beastie Boys, all of which are Jewish.  As much as I want to sing the Psalms to a klezmer style, I can't say that this is "the" authentic Hebrew style any more than the Beastie Boys.  Any serious student of music or history knows that, like language, the distinctives change too quickly to suggest we've retained those styles over 30 centuries.

In short, it seems that the "real" tunes used have been lost to history....perhaps for a reason.  We can infer some things were there from the instrumentation, but for our purposes, we are left to derive a tune according to the mood of the text.

In other words, according to the nature of music--poetry with a tune--whereby we receive the lyrics.  Our question is then; Are the lyrics Biblical, and does the tune fit the lyrics?  A bad example I remember is a little ditty of Proverbs 12:22, "Lying lips are abomination to the Lord", where the tune made one wish to skip and dance.  There is a place for dancing, Biblically speaking, but probably not when we're talking about abominations.  In the same way, when the Psalms talk about joy, one ought not to re-badge a funeral dirge for the accompaniment.

Perhaps what God intends here is that we think about these things, because when we consider whether the lyrics are Biblical, and whether the tune is fitting (not perfect, fitting), we are forced to do the work of the Bereans and truly understand the Scriptures.  As a pastor once rebuked a church I was attending, music is not just a time-filler, but rather a tool for communicating the Scriptures to both heart and mind.

So when we appraise church music, it's entirely Biblical and right to say "I think that this captures the joy of this song well," or "this Psalm, clearly call and response, really should have call and response instead of a solo in its presentation to the church."  It is, on the other hand, un-Biblical to say "this song has a beat that appeals to animal spirits" or "this song is soooo.....boring."

It is time for an armistice in the "worship wars."   The personal attacks, guilt by association arguments, and slippery slope arguments used by both sides indicate that there is a spirit involved.  It just isn't the Holy Spirit, to put it mildly.