Conversation so far:
What happened in 2006?
Sepultura's tenth album, Dante XXI, was released on March 14, 2006.
Who was Dante?
It is a concept album based on Dante Alighieri's The Divine Comedy.
Were they popular?
AllMusic gave the album 3.5 stars out of 5 and said that, "Overall, Dante XXI is easily one of Sepultura's strongest releases to feature Green on vocals..

Question: Who was Igor?
Self-contained rewrite: Who was Igor in Sepultura?