Until this controversy, I had no idea who Macklemore was. I do now — not because I went back and listened to his music, but because a fight over what he said during Ed Sheeran’s stadium tour has become a useful test of what free speech does, and does not, guarantee.

At MetLife Stadium in New Jersey, Macklemore told the crowd that a major reason he joined the tour was to stand in stadiums and say “Free Palestine.” Afterward, multiple venues told the tour promoter they would not host shows with him on the bill. He was removed from the remaining dates. Sheeran says that was the promoter’s decision, not his.