Demi Lovato Impersonates Cher, Christina Aguilera During Game of Musical Impressions With Jimmy FallonDemi Lovato Impersonates Cher, Christina Aguilera During Game of Musical Impressions With Jimmy FallonDemi expertly took on Cher, Christina Aguilera, and Fetty Wap as Jimmy fought back with his best Louis Armstrong and Dave Matthews. Erica RussellErica Russell