If you go by the numbers, Opeth may not be for you. You shouldn't really worry, though, because their longest song on this release doesn’t hit half the runtime of some of what Dream Theater have recorded. Ten minutes doesn't seem long at all when stacked next to a 32-minute Dream Theater track. You can safely inhale Opeth and exhale the way progressive metal should sound. If you are a musician, you hear master musicians playing their songs and you sigh; if you are not a musician, you probably still like the tenacity with which Opeth play their material.
And what is Opeth? Progressive death metal. Their material is both intoxicating and sobering, commanding the respect of metal fans around the world. Their singer toggles between growling and singing. This CD was recorded live at the Roundhouse in London on November 9, 2006. Per Wikipedia, it's a play on Iron Maiden's first release 
The Soundhouse Tapes.
Whatever.
It is more important to understand that, on their recent tour of the United States, they crisscrossed the country, bringing their technical and progressive material to thousands of people. Opeth is not a new band -- Blackwater Park was their first release I heard and that was in 2001. There is no new material on this release. There's no sneak peek at the next album. Instead, this disc is a snapshot of the band’s career that highlights their best studio recording efforts.
And so, with their trademark ferocious abandon, Opeth launch into "When" to kick off this release. Vocalist/guitarist Mikael Åkerfeldt, guitarist Peter Lindgren, bassist Marti Mendez, keyboardist Per Wirerg, and drummer Martin Axenrot then move into "When," a 10:28 track. There are clean vocal parts where you can understand the lyrics, and dirty vocal parts where you really have no idea what he is singing about. Lyrics take a backseat when Åkerfeldt growls.
Immediately prior to beginning "Ghost of Perdition," a 10:57 track, Åkerfeldt teases the crowd. Later, he introduces the next monster workout, "Under the Weeping Moon" and receives a warm response from the crowd. At one point, as he is talking, someone keeps yelling so he tells them to "shut the ___ up." The statement is delivered calmly and comes across as instructing the crowd to be civil to each other -- when I am talking, you be quiet. Parenting 101.
When Åkerfeldt introduces the band members, he warns the audience that he is doing "the big rock star thing" and apologizes. He goes on to say that when he introduces himself, he'd like to hear louder applause. It sounds cocky, but it is delivered with humbleness. He goes through each member of the band, ending with a request of Axenrot to quit playing the ride cymbal which had kept steady time during his monologue. He mentions that the band was formed when he was naked and in a sauna with another current band member and that Axenrot has an evil twin.
Opeth posess the right combination of humor and musical technique to make their long songs more than tolerable. They are a meaningful band in the genre and their contributions are solidly enjoyable.