They’re curious bedfellows—heavy metal and classic literature—but not as surprising as you might think. Consider how many heavy rock and metal bands—notably Led Zeppelin, Iron Maiden, and Metallica—have gone ekphrastic and based individual songs on works of literature. Still, few bands come to mind as having devoted an entire album to one book. Enter Mastodon’s 2004 release, Leviathan, inspired by and loosely based on Melville’s classic.

To an extent, all albums are “conceptual” in that they are totalities, but the term is most often used to describe albums in which the musical composition, lyric content, and album art integrate themes and establish a narrative. This is entirely true of Leviathan, right down to Paul A. Romano’s cover design of a white sperm whale breaching to toss a ragged whaling ship.

Structurally, Leviathan loosely adheres to Moby-Dick’s own meandering plot. Of the 10 tracks, the opening three (“Blood and Thunder,” “I Am Ahab,” “Seabeast”) and penultimate two (“Aqua Dementia,” “Hearts Alive”) directly address the novel, while the middle four, in imitation, deviate from the plot in order to explore elements of cetacean physiology and mythology and the human relationship with the sea (as on their debut album, Remission, the final track is about Joseph Merrick, the “Elephant Man”).

Sonically, Leviathan shifts from its initial tight-wound, furious energy toward slower tempos and more expansive melodic structures. It’s a deliberately alienating tactic, so that the listener feels adrift by the closing of “Hearts Alive.” The album’s 47 minutes feel like no time and an eternity—the very sensation I encountered when I read the book. And just as the album rewards repeated listens, reading the novel is even more satisfying a second time around.

Leviathan led me to Moby-Dick. But why did I embark on reading it? I don’t have a suitable answer other than perhaps I felt as Ishmael did; in my own way I had to “quietly take to the ship.”