I think we have to understand as well that music (and all that goes with it) is a tool only. It is not worship in an of itself, and it is not entertainment in and of itself either. It's just a tool that can be used correctly or incorrectly, and like with any tool, what is the correct way depends on the situation. We have to remember that just because it's Christian music doesn't mean it can't be used just for entertainment. It's not always limited to just worship. It can also be both at the same time. Even though worship is "for" God, there is nothing in the Bible to indicate we aren't allowed to enjoy it too.
It's the responsibility of whoever is leading the music to know what is correct for the situation. I watched a 45 minute long performance by a band one time where the lead singer was the obvious person in charge, and as she sang she never opened her eyes to look at the audience one time. She had a wonderful, powerful voice and the rest of the band were good musicians as well. But the problem was that this was during a worship service and she was so disconnected from the worship (or lack thereof) that the entire congregation could have walked out and I don't think she would have noticed. I think this kind of "performance" is where a lot of people get the idea that modern music is sinful in church. She was not "leading worship" at all. She was only performing in her own little world with no regard for how it was affecting the "worship" of the congregation. If this had been a concert only for the purpose of entertainment, that could have been fine. (Although even most big name secular bands tend to "tune" their performances depending on audience reaction.) But this lady wasn't "leading worship" at all so for me her performance seemed wrong fro a church worship service setting. On the other hand, I've seen others in her position that are true leaders who are in touch with God and are guided by him to provide music that leads the congregation to worship. These people are aware of the congregation and how they are reacting to the music, and will tailor what they are doing to whatever inspires the congregation to worship. That might be modern music, older hymns, or many times a combination. But it is obvious when they are actually leading worship as opposed to just performing music.
Maybe if more leaders of what we today call "praise bands" or "worship teams" would focus more on the actual leading and inspiring to worship, maybe there wouldn't be quite as much backlash to allowing more modern things into our churches from those who are more traditional. Just a thought.