Demi Lovato Joins Dan + Shay for ‘Speechless’ at Pre-Super Bowl Concert [WATCH]Demi Lovato Joins Dan + Shay for ‘Speechless’ at Pre-Super Bowl Concert [WATCH]While in Miami, Fla., for the Super Bowl, Lovato hopped onstage with Dan + Shay to perform their song "Speechless."Angela StefanoAngela Stefano