I would suggest a combination of the Chapman Studios and Shogun --> Down from the Sky LIVE from Chapman Studios. Listening to this helped me understand the voice dynamics of this band, because a lot of the screams are actually Coreys and not Matts and it's great to watch them switch between the phrases. Another thing worth mentioning is Paolos singing. Many of the clean parts in Triviums songs have Paolo singing a harmony to Matts part. I think it's a big part of their characteristic sound but rarely mentioned.