It seems that I can't answer my own question.

If you would like to try to answer your own question, you can possibly accept it and mark it resolved.

Thank you, michele fisher. I got it!

This generally refers to a very hard rock or metal band's music playing. It's also sometimes used in surfer or snow boarding culture. It is a commomly used slang term used mainly by young people to mean that the activity or music is being performed in a very good and most likely in an extreme way. It is very complimentary. The adjective "hard" is not always used to refer to "shredding". " Shred" alone is enough.