I went to Mayhem Festival 2013 in Burgettstown, PA with my friend and last time we went bands were signing and we didn't know, so before we left we grabbed some booklets from CDs we had in our collection. I took my Machine Head- The Blackening and he took his Amon Amarth- Twilight of the Thunder Gods, Children Of Bodom- Relentless Reckless Forever, and Machine Head- The Blackening Booklet. We got there and Machine Head wasn't signing this year, so I found out that Amon Amarth and Children Of Bodom were, so I went and bought their latest albums and got in line to have them sign them (pic of the C.O.B. booklet in next update). They seemed really cool guys and they put on a great show to open up the main stage. So next time they come to Pittsburgh, I'll go and see them again.