What I don't understand is why this has become such a problem. When I was first married, we attended a wonderful Methodist church which had balance...a rousing traditional opening processional hymn, a low church hymn, a praise chorus, a traditional choral anthem, and a high church recessional hymn. I think this is a good mix and has somethingwhich appeals to all, plus allows a continuation from generation to generation.
All I have seen around here for the last ten years is "groovy" music, and don't get me started on skits and "sacred dance."
One of the big problems I see is what I would label deceit. Lots of 'Praise and Worship' leaders come into churches claiming they'll do a 'blended' service including hymns, and before long they're doing entirely choruses with one verse of "Amazing Grace" and calling it balanced.
I know of many people who endure awful music in formerly good churches because it's tough to leave a church, and to leave it for music is even tougher.
To tell you the truth (and this won't be popular), I believe Satan is using music to tear churches apart, and the few people who are willing to stand up and be counted in keeping theological and musical integrity in churches (in many cases) are being punished.
I have several good book references on the subject if you're interested.