Coldplay was joined live on stage by Iranian actress, Golshifteh Farahani, at a huge concert in Buenos Aires. Together they performed an Iranian song called "Baraye."
The performance was to show support for the situation in Iran, where there have been recent country-wide protests after the death of a young woman in police custody.
Iranian singer Shervin Hajipour performed the song a month ago on social media and since then it has become the unofficial anthem of the turmoil in Iran. While Coldplay and Farahani performed in the River Plate stadium, Hajipour's original performance was played on the stadium's big screens.
Coldplay is currently in the middle of a ten sold-out show run in the Argentinean capital. Their performance was broadcast to thousands of cinemas in 81 countries around the world.