Wouldn’t the distinction here be whether or not the Republican convention is an event staged for the audience in the convention center in Minneapolis or an advertisement for the Republican Party intended for a larger audience. A public performance license would cover the first situation (including any news coverage) but probably not the second (the Palin/Barracuda footage used in a campaign ad.

I know something of the music rights issues for figure skating. The blanket public performance license obtained for competitive events covers the arena performance and broadcast of the event. It doesn’t automatically cover commercial exploitation of the event, so DVDs sold of the competitive events often have other music dubbed in. Professional exhibitions always have to individually license songs, which means skaters may not be able to skate to their preferred music if the rights are more expensive than producers are willing to pay for.

Because there has been a flurry of these rights complaints, I am assuming that what the artists are really looking for is that their music be left out of any later rebroadcast or video compilation of the event. And to make their political leanings clear.