@Irene and those haters.

AT least she sang live. What's the problem with shaky voice?? Did you go to Monster Ball Tours?? a lot of pre-record vocals and Gaga's shaky voice too. So stay mad.
Britney may not has a great voice like Christina Aguilera, Adele or Kelly Clarkson, but for this era she's going live. I can see from her L.A concert (hours ago), the improvement was getting higher. Surprise?

Paris Hilton, Perez Hilton, Nicole Richie, Kim Kardashian, Justin Bieber, Taio Cruz, BigTimeRush and more artists already praised her concert. SO who are you to judge?? Such a dumb-ass and mentally unstable.

In the mean time, I Wanna Go is climbing on iTunes.
This epic music video will be released tomorrow! YEAY!!!