"I met Shakira yesterday!!! I'm still trying to figure out what she said... Oh And I busted out some of my dance moves for Usher!!! He was intimidated..." Country star Blake Shelton jokes about meeting his two new co-judges on U.S. reality show The Voice. Shakira and Usher will join the panel of mentors next year (13), temporarily replacing Christina Aguilera and Cee Lo Green for season four.