... featuring only musical acts whose music Donald Trump is using at his political events, even though they've asked him to stop?
Trump isn't breaking any US law by doing this, as far as I know. But traditionally, if a musical act asked a politician to stop using their music, they'd stop. One more way that Donald Trump is new and different. One more way he's an asshole.
Adele, the Rolling Stones, Neil Young, Bruce Springsteen, REM, Elton John, Luciano Pavorotii, Queen, Aerosmith... Those could be some really kick-ass concerts. In between sets they could play records by George Harrison, whose estate has asked Trump to stop using his music. (I'm not sure whether Twisted Sister would fit in in this line-up, or if they would be interested in participating: front sister Dee Snider asked Trump to stop using their music, and Trump actually stopped. Apparently Snider and Trump are old pals.) And the fact that every single one asked Trump to stop using their music, and he didn't... Those acts have a huge amount of fans. Concerts like these, with the musicians free to say political things between songs, might get a lot of people interested in politics who otherwise ignore it.
Admit it: this is not the kookiest political idea you've ever heard. It beats talking to an empty chair hands-down.