Do you know Screamo?

Our band, Chase Rock, was performing at a benefit concert this past Friday along with two other bands. Our band plays mostly classic and modern rock. www.chaserock.com There were about five hundred in attendance for the show. We we're hoping for more, because it was a benefit for a young man who survived a terrible car accident. His name is Casey, and you can find out more about him here: http://www.caseybicknell.com/ 
Anyway, as the first band took the stage we were introduced to what we though was some type of death metal music. I know I'm probably showing my age right now. The music was like heavy metal with the singer growling into the microphone. I wasn't sure if he was growling words or just sounds. It was the growling part that I didn't get, but the young kids were into it, forming a mosh pit, and doing their thing. It wasn't until my friend's fourteen year old daughter informed me that the type of music we were listening to was called Screamo. I would have named it Growlo, but whatever works. They were nice kids, and everyone had a good time, some with ear plugs. Tell me what you know about Screamo below...