 That's actor Michael J. Fox joining the band Coldplay on stage for the final two songs of their set, jamming with a guitar to Humankind and Fix You. Chris Martin, the band's lead singer, giving a shout-out to Fox, whose guitar playing in Back to the Future, Martin said, inspired the band when they were just kids. Pretty cool. When we come back, the sky's the limit for a father-daughter duo in the sky.