Coldplay frontman Chris Martin graced a mass of Kings of Leon fans with his pretty face yesterday. He joined the band to assist with the song 'Fans' during their set in Glasgow at Radio One's One Big Weekend. Coldplay headlined the festival the night before, and Martin stuck around long enough to make one more appearance.

Kings of Leon singer Caleb Followill introduced Martin to the fans as "the second most famous singer here today." He said Martin told them he wouldn't sing, but said "we'll see" about that. Martin did provide a little vocal assistance, but mostly he just strummed the guitar.

It was a big day for Coldplay, given that 'Ghost Stories' became their sixth number 1 record later that evening. 'Ghost Stories' became the fastest selling record of this year after moving over 168,000 units since its release a week ago.