The music must match the message and not detract or distract from it.

Says who? Who will be the judge? What kind of "objective" measure could possibly be used to judge the appropriateness of the music? Katrina's point is that music is very subjective. Whether a tune is expected to be in a bar, sports event, or whatever, is completely subjective even within a single culture. Even individuals may change their tastes in music over time. What sounds "unchristian" one year may be exclusively Christian to him the next. It's patently absurd to suggest any kind of objective judgment of music for the church.

But does the music, per se, really matter?

Of course the music matters, but only subjectively. It matters to you that church music not sound as if it belongs in a bar or sports event. It might matter to another believer that it not sound like a stuffy, old hymn, else his worship is disturbed. There can be no authority to render objective judgment upon musical notes.

But within a culture, the connotative meaning of the music is well understood.

In a word, bull! If you limit that "culture" to a tiny subculture, this statement becomes less bull. The music my children listen to is very different than the music I prefer. When they hear a riff from their preferred style, it may mean one thing to them and a totally different thing to me--yet we live in the same culture. The same goes for music within a worship setting. Hymns common to one denomination are often not appreciated in another, even though the tunes are strictly limited to Christian settings. There is no common, connotative meaning to music unless the subculture is very narrowly limited; to be truly consistent, such that a judgment may be reasonably rendered, this subculture must be limited to a single person--thus the subjective qualification.

Music is completely subjective, even accounting for some common, cultural overlap in tastes, especially when judged as worshipful or not. If churches used music limited to that which was agreed by the lowest common denominator, congregations would be very small indeed and highly fractured (more so than even our numerous denominations today).

As for the musical instructions in Scripture, you may be under-informed. ALL of the Hebrew Tenakh (and Aramaic) was written to be sung. The original manuscripts (and faithful copies) contained musical notation right there in the Word. It was originally written this way. Many unfamiliar with Hebrew mistake this notation for vowels, but Hebrew has no vowel markings in the original Word (yod and vahv notwithstanding). (Vowel markings weren't even invented until hundreds of years after ישוע (Jesus)'s days on Earth.) Each human author of the Word had a different musical style, too, that can be seen in the musical notation. Apart from the text, we can identify which Psalms are David's because his musical style was so unique. This musical notation even shows us the tetragrammaton, YHVH, is three syllables, not two. (This means, while "Yehovah" might be a correct pronunciation, "Yahweh" cannot be.) If the Scriptures are to be used to limit musical worship, then we should be singing the Scriptures themselves according to their own notation and nothing more. Even the old hymns, then, would be musically heretical. And trust me, it would sound very different than the "old" hymns.