Long before Paramore released their new album This Is Why, Hayley Williams was talking about how Bloc Party was Paramore’s “number one reference” for the new LP. Starting next month, Bloc Party will open half of the shows on Paramore’s North American arena tour. Right now, Paramore are playing in the UK with Bloc Party. Last night, that tour came to the O2 Arena in London, Bloc Party’s hometown. During their headlining set, Paramore covered “Blue Light,” a classic from Bloc Party’s 2005 debut Silent Alarm, with that band’s frontman Kele Okereke.

When Kele came to the stage last night, Hayley Williams told the London crowd, “Bloc Party has been a huge influence on Paramore since we were little kids, you know? Picking up guitars and writing songs for the first time. And we’ve grown up with this band, the same way that a lot of you have grown up with us and probably have grown up with Bloc Party as well. So it only feels right to sing a song together that I used to cry to in my car. And maybe we can all cry together.”

From there, Hayley Williams and Kele Okereke sang a stripped-down version of “Blue Light.” They took turns on the verses and then sang harmonies on the chorus, and Williams, who seemed overjoyed, kept throwing in little interjections: “I can’t believe this.” Below, watch a fan-made video, via Brooklyn Vegan, and listen to the original “Blue Light.”