With eleven consistently excellent tunes, Mastodon's sixth full-length, Once More 'Round The Sun is nothing if not an exercise in subtly edging towards the mainstream without ever sacrificing any of their considerable metal pedigree. After all, few bands experience as much "don't, whatever you do, sell-out" pressure as Mastodon seem to – from a portion of their fan-base that just can't get their collective heads around anything since the band's 2002 debut Remission.

What they're missing though, is that regardless of how overtly melodic some of Once More 'Round The Sun might be in comparison to the earliest material, a band as progressive as Mastodon would never be truly selling-out. They are merely developing and evolving their sound in line with what motivates them as individuals and as a collective. There's a difference.

As with 2011's The Hunter, a record that, in comparison to its freakishly epic, concept-based predecessor Crack The Skye, seemed just a little too disposable (what record wouldn't have?); Once More 'Round The Sun also eschews any semblance of theme in favour of balls-out rockin' songs. Only this time they're some of the band's best stand-alone compositions to date.

Where The Hunter seemed perhaps a little forced in its tangential digression from the album it followed, Once More 'Round The Sun appears far more relaxed of mood, more comfortable in its own skin perhaps. The result is a far less burdened aura – uplifting and psychedelic at times – with tracks 'The Motherload' and 'High Road' breaking genuinely new melodic ground for the band while still being unmistakably Mastodon.

Fear not though, those of you trapped in a vortex called 2002: the bludgeoning riffs are still in place (check out 'Chimes At Midnight or 'Ember City' for confirmation) and, if anything, are only accentuated by the light and shade that the record consistently offers. Worth mentioning too is that, with gritty but polished production duties overseen by Nick Raskulinecz (Foo Fighters, Deftones, Rush etc), Once More 'Round The Sun's many positives are consistently seen in the best possible light.