SPIRITBOX - Watch 9 Year Old Girl Crushing Holly Roller at America's Got Talent, Plus The Band Invites Her To Perform At London Show (VIDEO)

She looks like a princess, but sings like a heavy metal warrior! ) year old girl from the UK, Harper performs "Holy Roller" by Spiritbox and shocks the judges with her surprising voice.

The band invited her to their yesterday's show in London on stage to perform with them. Watch it all below!