Crack the Skye is the fourth studio album by American progressive metal band Mastodon, released on March 24, 2009 through Reprise Records. It features seven tracks and runs at 50 minutes and 6 seconds. The album debuted at number 11 on the Billboard 200, selling 41,000 copies in its first week. In Australia, the album debuted at number 19. It had sold 200,000 copies in the US as of September 2010, making it one of their highest selling albums to date.
According to an interview on the DVD The Making of Crack the Skye, this album represents the element of aether, which is represented by the souls and spirits of all things, a theme closely related to the context of the album. Because the elements of fire, water and earth have already represented by the band's first three albums Remission, Leviathan and Blood Mountain, respectively, the element of air is the only classical element which has yet to be represented by a Mastodon album.
Drummer Brann Dailor described the album as more "focused" than its predecessor, Blood Mountain: "Maybe there was a deeper heart to this record that needed more exploring… We got more involved with feeling the vibe of the record and everything feels more