The 55th Grammy Awards kicked off at Staples Center Sunday afternoon with the announcement of the first winners at the pre-telecast ceremony at the Nokia Theatre.Mumford & Sons, nominated for six awards, collected their first Grammy for “Big Easy Express,” a long-form video about the U.K. band’s tour with Edward Sharpe & the Magnetic Zeros and Old Crow Medicine Show. Rihanna’s “We Found Love,” a track with Calvin Harris, took best short form music video honors. The Recording Academy will hand out 70 awards at the afternoon ceremony, hosted by David Alan Grier. Another 11 – including album, record and song of the year and best new artist – to be announced during the CBS telecast this evening. Stay with Variety.com for ongoing updates through the day.