MASTODON
w/ Intronaut and Kylesa. Starlite Room (10030-102 St). Sat, Apr 25 (8pm). Tickets: $29.50, available through Ticketmaster or at the door.

Not since Boney M occupied the Top 10 has Russia’s greatest love machine been given such an impressive makeover.

It took 30 years for Mastodon to resurrect the nigh-unkillable Mad Monk with their fourth release, Crack the Skye, and they’ve done it in a highly original way.

“Okay,” admits singer/bassist Troy Sanders via cellphone as he walks through windy Albuquerque, battling sudden squalls while he explains the plot of their latest album. “On paper it definitely seems kind of strange — it’s about time travel, astral projection, and Rasputin, and if you just look at it that way, it doesn’t make a lick of sense.”

In many ways, even after Sanders’ explanation, it still doesn’t make a lick of sense — but there is a plot, and it does hang together if you don’t scrutinize it too closely. In short, Crack the Skye is a concept piece that follows the spirit of an astral-travelling paraplegic who finds himself without a connection to his body after drifting too close to the sun ... after which he’s inserted in the Russian mystic whose influence on the czar’s family through the early part of the 20th century led to numerous failed attempts at assassination.

Got it? Good — though it isn’t really necessary. Mastodon has done this before, after all, with a concept album based on Moby Dick (2004’s acclaimed Leviathan), and if there’s one thing that this band has proven, it’s that they never let the idea supersede the actual music. Shuck the story if you must, Crack the Skye is still great Mastodon music, as viscerally thudding as anything they’ve ever done. While it might seem as though they’ve headed into somber prog land with titles like “The Czar: I. Usurper — II. Escape — III. Martyr — IV. Spiral,” the fact is that Mastodon can’t quite shake their metal roots, even as they add touches of banjo and mellotron to the mix.

The result has gotten the Atlanta four-piece some of the best reviews of their careers, though Sanders (along with drummer Brann Dailor, guitarist Bill Kelliher and guitarist/vocalist Brett Hines) are quick to note that reviews don’t determine how they judge their own work.

“It’s an excellent compliment when listeners say they like what we do, don’t get me wrong,” he says, “but we didn’t write the album to please a particular group of people. When you create art you want people to hear it — it’s not there for just a few to discover.”

Hold on. Even with esoteric topics like astral travel and historical figures, Mastodon expects to reach a wide audience? “Well,” he says after a pause, “these are the topics that fascinate us. We lay them out on the table and kind of create from there. It’s very collaborative — and we only put these interests together if they make sense.”

So if someone has an obsession with Aztec culture and the coming apocalypse in 2012, it may not necessarily make it in?

“Exactly,” Sanders laughs. “But we do like to keep it interesting — and you hope that your fans will stay with you on it, but there’s no guarantee. Besides, for us to work, we all have to be on the same page, or nothing gets done.”

From the way Sanders describes their democratic modus operandi, it seems amazing that anything gets done in the Mastodon camp. But somehow four exploratory albums of pulverizing hard rock have come out of this partnership, all skirting the line between brutal metal riffing and thoughtful arrangements, with enough eye-opening sonic touches to keep it interesting for both band and listeners.

“We don’t like to stand still,” Sanders says. “There are just so many things we’d like to try: throwing a banjo intro on one of our songs was just one of them. The possibilities are unlimited, but we also like to keep it rocking.”

Feeding the body as well as the mind, right?

“Exactly — we’re going at this one caveman step at a time.”