When it comes to musical forms, CofCs have struggled in the past decade or so. Traditionally, we have held a pretty strict diet of a cappella (voice only, that is) music inside the worship assembly. There seems to be a growing consensus, however, that this is changing. Even the views on which worship styles are necessary, acceptable, or evil are slowly being reshaped. There is much interesting discussion to be had about this topic.
Worship styles have been a topic of debate among CofCs for quite some time, possibly due in part to the alteration in our understanding of what qualifies as worship. There are many positions on this debate, but I shall oversimplify and categorize them accordingly.
- Anti-Instrumental. This is a rather common form of reaction to the notion of instrumentation in worship. Anti-instrument has its basis in history . . . sort of. Here's the basic idea: since the first-century church did not use instruments, neither do we. This does not appear to be an unfair treatment at first glance, but we must consider how small an amount of evidence is available, as well as the circumstances under which worship occurred. More later, if you behave.
- Pro-A Cappella. This is a growing group, and is actually distinct from anti-instrumentation in that it sees no problem with using instruments, but prefers a cappella over them. While I'm not certain as to whether many people view themselves with the label "pro-a cappella," it does not seem unfair to provide such a title. 
- Pro-Instrument. This is essentially identical to the pro-a cappella group with some substitution or term reversal. For them, it is merely a preference of instrumental worship over non-instrumental.
- Anti-A Capella. This is a minority group, if it exists as a group at all. While there are certainly those who hold this position, it does not yet appear to be a widely voiced opinion. The gist of this concept is that instrumental worship is preferable to and better than voice only. I include this category more out of the possibility of its existence than for hard fact of its presence. Whether there are any CofCs that are proponents of this concept remains to be seen.
Here is another way of looking at the group: a spectrum! 
These are the 4 basic (possible) views on worship styles in the CofCs now (at least as interpreted by yours truly). On the spectrum, it is easier to see how the negative forms (anti-groupings) are in greater opposition than are the positive forms (pro-groupings).
This is all for now, lest the post get ridiculously long. Next time we can enter into a discussion and critique of all these stances.
Grace and peace,
 I actually got this term from a preacher (Barry Stephens) whose church (Monterey Church of Christ) I have been attending while studying theology at Lubbock Christian University, so the credit goes to him for the term. I cannot say whether he "coined" it or got it elsewhere.
 It is only by coincidence that, at least for my laptop screen, the Anti-A Cappella end is slightly off the edge of the map. Even so, it's still a bit funny to me that it turned out this way.