Green Day, Mick Jagger, Lorde, Blondie and REM have all signed an open letter to prevent the unauthorised use of their music at political rallies.Jagger, who has previously denounced Donald Trump for playing The Rolling Stones at his rallies, joined forces with the extensive list of artists and the Artists Rights Alliance (ARA) ahead of the US elections.In an open letter penned by the ARA, they demand that the major US national political party committees “establish clear policies requiring