When Ad Majorem Sathanas Gloriam was released in the United States during the summer of 2006, Norway's infamous Gorgoroth was experiencing considerable turmoil.

Lead singer Gaahl was serving time in a Norwegian prison for severely beating a man in 2002 and threatening to drink his blood; founder/guitarist Infernus was looking at possible incarceration for, Norwegian prosecutors alleged, doing nothing to stop a rape that a friend allegedly committed in his presence; and longtime bassist King Ov Hell had left the band.

Of course, lineup changes are nothing new for the Occult-loving Gorgoroth, which has been a revolving door over the years.

But despite all the controversy and lineup changes, the band has had no problem providing excellent albums -- and Ad Majorem Sathanas Gloriam is no exception.

The lineup on this 2005/2006 recording includes Infernus (the only remaining member of Gorgoroth's original 1992 lineup), Gaahl (who hadn't left for prison yet), King Ov Hell and drummer Frost (of Satyricon and 1349 fame), and together, these Scandinavians provide a vicious, harsh, nasty dose of death metal-influenced black metal.

Gaahl's raspy vocals sound downright evil, and Frost plays his blastbeats with tremendous conviction.

Actually, everyone on the album plays (or, in Gaahl's case, sings) with great conviction, which partly explains why this 31-minute disc is as unsettling as it is.

There aren't that many albums in either death metal or black metal that can honestly be described as unsettling; in so many cases, extreme metal has come across as tongue in cheek more than anything.

But Slayer is an example of a band that can be genuinely unsettling, and the same goes for Gorgoroth -- whose Ad Majorem Sathanas Gloriam is an engaging, consistently inspired addition to their catalog.