Coldplay and Kings Of Leon both headlined BBC Radio 1’s Big Weekend on separate days in Glasgow this past weekend but Chris Martin stuck around after his set to join Kings Of Leon on stage. KOL frontman Caleb Followill introduced Martin as the “second most famous singer here today,” obviously after Katy Perry who would perform later that night. Martin sang backing vocals and played guitar on “Fans,” all while wearing the same outfit as Followill. Watch video of the performance below.