Neil Young, Mick Jagger, Keith Richards, Sia, Lorde, R.E.M., Green Day, Pearl Jam, Blondie, Steven Tyler, Elvis Costello and other artists have signed an open letter demanding that politicians get clearance to use songs before playing them at campaign rallies.

The letter calls to "establish clear policies requiring campaigns to seek consent of featured recording artists, songwriters and copyright owners before publicly using their music in a political or campaign setting,” as Rolling Stone reports.

"As artists, activists and citizens, we ask you to pledge that all candidates you support will seek consent from featured recording artists and songwriters before using their music in campaign and political settings,” the letter continues. “This is the only way to effectively protect your candidates from legal risk, unnecessary public controversy and the moral quagmire that comes from falsely claiming or implying an artist’s support or distorting an artists’ expression in such a high stakes public way.”

Neil Young has been particularly vocal about Donald Trump's use of "Rockin' in the Free World" at rallies, and this week wrote "Imagine what it feels like to hear 'Rockin' in the Free World' after this President speaks, like it is his theme song...I did not write it for that." The Rolling Stones, Linkin Park, and R.E.M.'s Michael Stipe have also asked Trump to stop using their songs at rallies.