Well, it seems we've gone mainstream. Mastodon is a band that's able to combine elements of sludge metal and elements of progressive metal as well to make one high energy package. From albums like Remission to Leviathan to Blood Mountain, they have been known to boggle many minds of listeners with the very complex drumming skills, and hardcore, hypnotic elements. You will be amazed by how well they keep up with this controlled chaos.
As for Crack The Skye, alot of fans find this to one of, if not, the best work from the band. Why not? They have everything a prog fan needs. The music can get a bit monotonous at times but sometimes, you're just so hypnotized by the music you won't care. With tracks like The Czar, Divinations and Quintessence I don't see how you could go wrong with this at all. Yeah, its only seven tracks but I'm not really complaining because I know smaller setlists for one. As for the final, 14 and a half minute long track, The Baron, all I can say is that they change up quite alot in that one song. This ultimately makes it very interesting and easy to move on with. Very hypnotic, heavy, progressive and of course, very, very good as well.
I can only say a 10/10. I am the Grim Reaper, signing off.