Breakthrough Artist of the Year Idina Menzel, who sung the smash hit "Let It Go" from the movie Frozen, is hitting the road in 2015. In addition to her work with Frozen, Menzel has also acted in a number of Broadway musicals and won a Tony award. But "Let It Go" has defined the multi-talented artist this year. The Frozen soundtrack spent a number of weeks at No. 1 on the Billboard 200 and has sold more copies than any other album in 2014.