NBC's The Voice started with a brilliant interpretation of Gnarls Barkley's super hit Crazy. Adam Levine, Christina Aguilera, Blake Shelton and Cee Lo Green join together not just as coaches, but as profesional singers.
Here's what someone on Youtube had to say about the performance of this four superstars:

Adam has probably got the most attractive voice..
Blake has without doubt the best country voice.
Ceelo Is a genius!..
Christina is the goddess of Music!

The Voice UK comes to BBC One