In March 2025, founding guitarist and vocalist Brent Hinds departed Mastodon after twenty five years, and then five months later he was tragically killed in a motorcycle accident in Atlanta. As such, few albums in history have arrived carrying the emotional weight of Marrow Deep.

The band have been quite explicit that they would rather return to writing about fantasy and mythology, but unfortunately their lives keep providing them with harrowing raw material. What they’ve chosen to do on Marrow Deep is to make a clear, firm and moving that statement that whilst the Mastodon story may contain enormous tragedy it does not end with it. They haven’t tried to replace Brent Hinds, knowing that you cannot replace a founding member of twenty five years, and instead they’ve expanded the lineup by adding two new members, and inviting a remarkable collection of guests into the fold.

The most audacious new addition is keyboardist João Nogueira whose role is considerably more front and centre than textural studio embellishment. The keyboard work on this record is wild, unhinged and gloriously cartoonish in the progressive rock tradition of Rick Wakeman and Keith Emerson. It’s a bold and risky move, but these elements prevent Marrow Deep from getting bogged down in misery, injecting colour, drama and theatrical grandeur to keep the album moving even in its most emotionally devastating moments.

Mastodon can write multi-part metal suites in their sleep, having been doing it since they were young to an unbelievable standard, and so the question here is not whether they can do it again, but how to address their own situation through this medium. With endless endlessly satisfying riffs from Bill Kelliher stacked on top of each other, every song is a multi-section odyssey. The first half of the album is a sprawling and ambitious prog jam, whilst the second half is slower, lonelier and more reflective. In The Ruins has the same quality of loneliness and sparse sadness as Metallica’s One, and the tribute to Brent Hinds Snakes For Dinner is one of the most powerful songs Mastodon have ever written. It will reduce long-term fans to tears, with a powerful coda from Josh Homme at the end.

We live in an era of over-compressed, pinging machine gun bullet snares, and Brann Dailor’s drumming is a perfect antidote that’s a masterclass in personality and dynamic variety. His voice throughout the album is remarkably sweet in contrast to Troy Sanders’ gruff bellowing, as the drumming conjures dramatic storms and raging waves. This isn’t a starting point in their discography, and newcomers should probably experience Leviathan or Blood Mountain first and work their way forward, but if you’ve ever loved a Mastodon album then Marrow Deep is a profound gift. They’re still here despite everything they’ve lost, making music at the highest level and refusing to stop.

Bill’s riffs are terrific, Brann’s drumming is as expressive as ever, Troy’s vocal performance is really bloody strong, and the two new members are clearly injecting vivacious youthful energy into the whole thing. Despite the unimaginable tragedy that surrounds it, the album is balls-to-the-wall, sweat-drenched fun, and the greatest tribute Mastodon could have paid.