Chris Martin and his actress wife Gwyneth Paltrow thrilled a sold-out crowd at London's prestigious Royal Albert Hall last night (27SEP06) when they joined hip-hop star JAY-Z on stage. The Coldplay frontman collaborated with Jay-Z on his new album Kingdom Come, sparking rumours the pair would duet live as part of the rapper's two London shows this week. But no one expected the singer to be joined by his wife too, who provided backing vocals for SONG CRY. She has previously appeared onstage with pal Sheryl Crow. Martin performed an untitled new song from Jay-Z's forthcoming album, as well as HEART OF THE CITY (AIN'T NO LOVE) from classic record THE BLUEPRINT. Another star helping out his hip-hop friend last night was Nas, who sang three songs. Jay-Z was the first rapper to perform at the Royal Albert Hall venue. He was accompanied by a full 25-piece orchestra.