Singer Rihanna arrives at the 53rd annual Grammy Awards in Los Angeles, California February 13, 2011.

Country trio Lady Antebellum and Canadian rock band Arcade Fire lit up the Grammy Awards on Sunday, winning key prizes in a ceremony packed with upset victories and a humiliating setback for Eminem.The hip-hop star, who led the field with 10 nominations and had been expected to dominate the ceremony, ended up with just two awards in the rap field.Lady Antebellum, on the other hand, picked