It seems like for the most part contemporary music won out. Where there was a struggle, new music won. Choruses and worship bands pretty much predominate evangelical churches, and quite a few mainline churches too. It's not like you can't find traditional Christian church music in an evangelical church, can't find a piano and a hymn book somewhere (or even, on very rare occasions, an organ), but, for the most part, that's not what happens in evangelical churches on Sunday mornings.
The new classics of Christian worship -- the songs that everyone knows -- are "Mighty to Save", "Lord I Lift Your Name on High", and "Shout to the Lord".
What I haven't seen, though, is a good account of why contemporary music won. The sense, at least for those who still sometimes pine for older songs and so still talk about those days of hymns of yore, seems to be that the change was inevitable and inexorable. That it had to happen.
I don't find the Hegelian idea of telologically-determined history satisfying, though, so I'd like to know why contemporary music, which was so controversial for so many, has come to be so broadly accepted.
- The Scorsese thesis: The generational center of gravity has shifted, and those who came of age after 1960 now have the most power in American Protestant churches. As pastors, elders, board members, congregants, financial supporters, and as worship leaders. As Julie Ingersoll points out in "Contemporary Christian Worship Music" in Religions of the United States in Practice volume II, "Baby boomers were the first Americans to grow up with popular music as a continual backdrop to their lives." In the same way Martin Scorsese makes the soul of his movies pop music, Americans now find their souls moved by contemporary music.
- The church growth thesis: Those who wanted traditional music in churches focused on traditional music, but those who wanted contemporary music talked of it only as a means. The ends were things broadly agreed upon, such as growth. The church growth movement, with seeker sensitive mega churches, used contemporary music and demonstrated the usefulness of contemporary music not for its own sake, but for the sake of growth. As evangelical churches copied the model of Willow Creek, for example, they adopted the music without making arguments for the music itself, focusing instead on getting people into church. By whatever music necessary. Contemporary music "worked," according to the definition of growth, which most in these churches agreed was a good definition.
- The slipperiness of the slope thesis: A lot of the arguments against contemporary music depended on bad things -- horrible things -- resulting from abandoning hymns and traditional worship music styles. There were arguments from the mild, e.g. that Christian beliefs would basically wither in the "shallow ground" of choruses, to the extreme, e.g. that drums were linked to and would lead to Satanism, which depended on a clear connection between contemporary music and bad, bad results. Those arguments just didn't hold up. The doom didn't follow from contemporary music, and the traditionalists often ended up looking silly, and like they were just nostalgic for some imagined past, or, worse, cranky because they were losing control and ownership.
- The industry thesis: No one promotes hymns. There's no industry supporting and promotion and pushing traditional music.
- The compromise thesis: About half of all Protestant churches have "blended styles," according to a 2002 report from Barna. Seventy-three percent have multiple services, and half of those with multiple services have one with traditional music. In evangelical churches, "blended styles" sometimes means one hymn in a service, or a re-mixed hymn such as "Amazing Grace (My Chains are Gone)." Contemporary worship music, in these ways, is able to accommodate some traditionalism, where traditional worship music doesn't adapt and accommodate so easily. Even if a church is split down the middle on worship styles, contemporary music is more likely to appease more people, and that makes it an appealing choice, especially when church leaders are weary of "worship wars."
One place to start would be the question: why this music?