Rihanna, Drake, Janelle Monae, Justin Beiber and Others Spotted at Grammy Rehearsals! (Pics, Video)

Jaden Smith, Justin Bieber, Usher, Janelle Monae, and B.O.B were also rehearsing for the Grammys the weekend. 16-year-old sensation Justin Bieber was snapped rehearsing for his performance alongside his mentor Usher and his Hollywood friend Jaden Smith. Check the pics:

Too Cute. Jaden Smith will perform alongside Justin Bieber and Usher, with whom he collaborated on the song "Never Say Never."

Janelle Monae

B.O.B.

And, despite reports that Rihanna is suffering from laryngitis and bronchitis, she managed to hit the stage with Drake. Check out the video:

That Bruno Mars is damn talented!!
Which performance are you excited to see?