Coldplay may be illiterate in football, but the crew has rehearsed every second of the Super Bowl 50 halftime show. Frontman Chris Martin says they have watched all of the past halftime shows many times to prepare for the big moment. On the field, they will be joined by Queen Bey and at least one other special guest. That mystery performer may be Bruno Mars whose appearance would be de ja vu for the Denver Broncos, which lost to the Seattle Seahawks in Super Bowl 48. But most importantly, Levi's Stadium has been in touch with the local utility in case the performers use up all the power in the place repeating the powerless Superdome in 2013.