There was probably a higher-than-usual tardiness rate at Twin Cities schools last Tuesday. Maybe the teens and tweens who attended KDWB's annual Jingle Ball were just tired, or perhaps they had laryngitis from screaming for much of the five-hour event.

Boys Like Girls, Lady GaGa, David Archuleta and T.I. performed. However, the most shriek-worthy moment was when Chris Brown took the stage with Rihanna. Images of the two during a duet of "Umbrella" were captured by thousands of cell phone cameras that lit up Xcel Energy Center.

If it weren't for the Jingle Ball, Rachel Murrary, a sophomore from Chanhassen, and her friends probably would have been doing homework. It was a Monday night, after all. "We're crashing at someone's house tonight, but we'll still go to school tomorrow," she said. "We kind of have to."

Sara Glassman • 612-673-7177