[10] In late 2012, Mastodon guitarist Brent Hinds mentioned in an interview that he had begun writing material for the band's next release.

[12] The band began recording in late 2013 at Rock Falcon Studios in Franklin, Tennessee, with producer Nick Raskulinecz.

"[16] Brann Dailor stated following about the album: "It's gonna be massive and insane, lots of epic greatness.

"[18] Oakland-based artist Skinner, who characterizes his work as "psychedelic nightmare paintings", created the album's artwork.

"[5] Michael Madden also praised the album in the review for Consequence of Sound, claiming that "Mastodon are starting to look more like that band's peers [Slayer], not disciples.

Nick Raskulinecz's eternally crunchy production helps them reach those heights on Once More 'Round the Sun, and, as Oakland artist Skinner's cover suggests, the record is vibrant, too.

"[21] Dom Lawson spoke highly of the album in his review for The Guardian, writing that "Once More 'Round the Sun sounds very much like the album they need to make to edge a little further into the mainstream – it has a largely straightforward air and a tendency to favour the big hooks of 2011's The Hunter over the labyrinthine weirdness of 2009's Crack the Skye.

"[23] Spin writer Johnathan Zwickel shared similar sentiments, claiming that "While the rest of heavy music's luminaries follow in their wake, Mastodon's sound – and their ambition – is bigger than metal.

"[24] Zoe Camp was more critical of the album in the review for Pitchfork, stating "it's possible to view Once More 'Round the Sun as a vow to honor their roots, even as they set out in search of broader horizons.

Evolution takes time, and Mastodon continue to publicly work out their growing pains as they determine which traits best represent the unified sound they've been chasing this decade."