Let me pose this question- maybe someone will know for sure. It seems like, in buying broadcast advertising, a customer can pay a premium for their ad to appear on a particular program, or they can "float" and their ads will appear wherever there's empty space. So, could it not be that Guitar Center bought an ad from a particular radio station, without necessarily intending it to air during Rush's show? Or perhaps they wanted it to air at a particular time of day, that just happened to be during that show.

I used to work at a newspaper, and the policy was that advertising didn't affect editorial content didn't affect advertising. It was a pretty progressive paper, and I know that several of the advertisers didn't agree with a lot of the things we did! But they knew that our product reached the people who would be likely to shop with them.