Mumford And Sons' Babel was named Album of the Year at the Grammy Awards last month. The win sent the disc temporarily back to Number One on the Billboard album chart, while pushing its sales over two million.  The band has been named one of the headlining acts, along with Paul McCartney, Bjork, Wilco and Tom Petty, for the 2013 edition of the Bonnaroo Music and Arts Festival, which will take place from June 13th through the 16th in Manchester, Tennessee.