Mastodon

When Mastodon turned ten in 2009, they didn't celebrate with a candle-adorned cake; they split our skulls open with Crack the Skye, a concept album that cemented their position as one of modern metal's most important bands. That's because it's catchy enough to clobber the Top 40 (the creeping chords and sky-scraping choruses of "Oblivion," the rail-jumping riffs and manic melodies of "Divinations"), yet complicated enough to leave prog junkies in a permanent tailspin (see: any song on this playlist). Kinda like such career standouts as "Capillarian Crest" and "Seabeast" — music that makes you scratch your head mid-mosh.

As for our Next Steps, they cover everything from fan favorites to insane examples of Mastodon's early days.

Here's how we can tell Mastodon weren't messing around on their first proper full-length, Remission: they named one of its many whip-cracking cuts "Mother Puncher." Which speaks for itself as loudly as any of the following riff-slingers and rarities: speaker-trampling live takes of "Megalodon" and "The Bit"; a spacey, synth-spliced instrumental version of "Quintessence"; a dot-connecting collection that skims the best songs from Mastodon's debut EP ("We Built This Come Death," "Shadows that Move") and 7-inch ("Deep Sea Creature"); and a highway-hitting ZZ Top cover ("Just Got Paid") that reveals the band's Southern rock roots.

How Mastodon went from being a bunch of dudes who met at a High On Fire show to an absolute force of nature is anyone's guess . . . until we examine the evidence, that is — a growing stack of head-turning guest appearances, brutal B-sides, and mind-melting platters that remind us of all that the word album used to mean. It's all here in our Mastodon Essentials playlist, a collection of 21st-century metal that could double as the soundtrack to hopping in a stolen car, hitting the gas— hard — and peeling out to the gate-crashing tune of "Blood and Thunder," devilish student/teacher duets with Neurosis' Scott Kelly ("Aqua Dementia," "Crystal Skull"), and a mud-slinging turn in Today Is the Day (featuring Brann Dailor on drums and Bill Kelliher on bass). Buckle up.