This Christmas, a very special musical comes to the big screen. In most musicals, the actors sing in studio months before even seeing an actual set. Then they mime the songs during taping.
The problem is that you lose much of the personality and realism when simply miming along compared to live singing and acting.
Les Misérables–starring Russell Crowe, Hugh Jackman, Anne Hathaway, Amanda Seyfried, and more–is different. The musical contains only live singing, a first in the industry.