camp rules

I have been checking out different sites for an InterVarsity student conference in February. One particular Christian camp has it written into their "Rules and Regulations" that there is to be no playing "rock music" or dancing. Unbelievable! I find myself wondering how they could still (if ever) have that as a rule. It just brings so many follow-up questions to mind:

Is it just rock that is disallowed? What about rap, disco, pop, or techno? What about country? What about Christian rock? Is that allowed? What if 3/4ths of the band claim to be Christians? What if we are reasonably sure that all of the band are Christians but they stick to secular radio and wouldn't be caught dead on WAY FM?

I just find it hard to believe that this document hasn't been updated in the last 40 years or so. Or maybe it's still a strong conviction. Lucky for me, I had the windows up as I blared U2 on the way in.