2009 release from the Atlanta-based Heavy Metal outfit. Mastodon has taken hold of the leadership of the New Wave of Progressive Heavy Metal. The band's 2006 major-label debut Blood Mountain spun off a Grammy nomination and earned Top 5 Best Album of the Year nods from Kerrang!, Revolver and Metal Hammer, and a Top 10 Rolling Stone. Now Crack the Skye, it's fourth original studio album, mines subject matter from czarist Russia and astral travel to out-of-body experiences and Stephen Hawking's theories on wormholes for an unrepentantly heavy aural assault that will shake the heavens.