Justin's 2010 VMA rehearsal [Video]

Justin Bieber fans were treated to a free, unannounced concert yesterday.

In advance of his performance tomorrow night at the MTV Video Music Awards, the teen singing sensation rehearsed outdoors for close to two hours near the Staples Center in L.A.

Bieber and his young back-up dancers went over every step of his performance, including his (scheduled) arrival in a red 1957 Chevy.

While