Saw this last night on AGT, and it was quite surprising.   They played a sweet kiddie piano version of Twinkle Twinkle Little Star over the entire package leading up to the performance.

My wife went out of the room to get something and missed it, so I had to rewind it for her.  Now I thought it was pretty funny, but I do agree with the judges.  All but 2 of them buzzed the act.  I don't listen to this kind of music on a regular basis, but when I hear it, I can tell the difference between good screamo and bad screamo heavy metal.  This was bad.  But the kids were cute and they got through.

Listen to 6-year-old Aaralyn and her brother Izzy playing their brutal track "Zombie Girl."