Pop superstar Miley Cyrus confirmed Wednesday she is joining the cast of "The Voice", NBC's popular singing competition show.  Cyrus will serve as a key adviser for all four teams, which will be coached by Adam Levine, Pharrell Williams, Blake Shelton and Christina Aguilera, who returns this season after sub Gwen Stefani's stint.  Cyrus will be performing the same role Taylor Swift filled during the 2014 season.  Season 10 of "The Voice" is slated to premiere on Leap Day, Monday February 29th on NBC at 8 PM ET.