On Sunday night, Pharrell Williams took to the stage in Baku, the capital of Azerbaijan, to round off the weekend's Formula 1 European Grand Prix entertainment. Enrique Iglesias and Chris Brown had played on the preceding nights.
In some ways, Pharrell was the most powerful man in town, even more so than F1 boss Bernie Ecclestone, and possibly, just for that evening, even more powerful than Azerbaijan's president, Ilham Aliyev.
The Aliyev regime was desperate to bring the glamour of Formula 1 to Azerbaijan, in the hope of detracting attention from its terrible human rights record. Formula 1, in turn, is desperate for big stars like Pharrell to draw younger people to the sport, whose traditional European fan base is aging fast. Pharrell is a globally respected star with nothing to lose.
Which is why the Sport for Rights campaign implored him to take a stand for free expression in Azerbaijan, a country where dozens have been imprisoned for speaking out against government corruption.
Prominent investigative journalist Khadija Ismayilova, who was recently freed from prison after human rights lawyer Amal Clooney took on her case, wrote on Saturday that Pharrell should not "participate in the lie" that Aliyev projects.
Director of the Institute for Reporters' Freedom and Safety Emin Huseynov, who was forced to flee the country, warned that stars like Pharrell should not be "complicit in the propaganda that attempts to gloss over human-rights abuses".
The irony of Pharrell singing his hit "Freedom" in a country with one of the lowest press freedom rankings in the world would have been too much.
Thankfully, Pharrell took heed of Sport for Rights' call. Introducing Freedom, he dedicated the song to the "youth of Azerbaijan, who "When they grow up they will change things not only here, but around the world".
To huge cheers, he added: "And no one can stop them. No one can block them", and repeatedly chanted "Freedom" - a word that, when used in protest, has landed many Azerbaijanis in jail.
Khadija Ismayilova said Azerbaijanis appreciated the gesture, telling me: "Chanting freedom is a luxury in Azerbaijan. It was great to learn that Pharrell Williams could give the audience a feeling of freedom and send a strong message".
Ismayilova said that Azerbaijani social media is now full of jokes about how Pharrell is likely to be fitted up on spurious drugs charges by the Azerbaijani authorities, a common punishment for those who call for freedom in Azerbaijan.
Pharrell's decision to speak out for freedom on stage in Baku will be such an encouragement to Azerbaijan's dozens of political prisoners, including some of the country's best and brightest youth. Sport for Rights is thrilled that he responded to our call to do the right thing, which comes in stark contrast to the many others we urged to use the Formula 1 European Grand Prix to speak out for human rights in Azerbaijan - F1 management, drivers, and celebrity performers - who shamefully allowed themselves to be used as propaganda to whitewash the image of the corrupt Aliyev regime.
Artists and athletes often claim to be apolitical. But they should remember that in countries such as Azerbaijan, where free speech is at a premium, their silence can be deafening, but their words can be powerful.