There are some bands that people consider to be truly special. They may not be the most commercially successful, or even the most notorious, but to those in the know they are spoken of in reverential terms; their music capable of touching places within that few manage. Savannah Georgia's Baroness are undoubtedly one such band. Their Red and Blue albums combined the heartwarming, homely aura of southern rock with a sludge infused take on progressive metal efficiently enough to have a profound impact upon the listener.

Even without its preceding EPs, their debut album Red would have been enough to cement them firmly within the 'best kept secret' category of most people's record collections. Their new double album Yellow/Green continues the colour-coded aesthetic of their previous releases and further expands Baroness' musical palette, building upon the melodic subtleties of preceding record Blue, and further distancing themselves from the guitar thunder of Red. It is an altogether more accessible take on their sound that will widen the band's appeal, but risks alienating their existing fan base, who perhaps a little preciously, may not want to see their baby unleashed upon a wider world.

Yellow leads the charge with introductory instrumental 'Yellow theme' evoking dark clouds gathering on the horizon, threatening to ruin a hazy summer's afternoon, before the bombast and rollicking chorus of 'Take my Bones Away' simultaneously provides the closest 'Yellow' gets to the volume of old whilst clearly demonstrating a more conventional approach to song structure. 'March To The Sea' follows and is infused with the beautifully nostalgic warmth of their older material, attached to a subtly addictive guitar lick that elevates the chorus into something special.

It is clear that a lot of effort has been put into the composition of the new songs. Red and Blue were at their most focussed when bludgeoning the listener with huge, heavy hooks and bellowed vocals, which would in turn peter out, leading the listener off the beaten track and down tangled, intricate paths of instrumentation; an adventure it was easy to become lost in and bewildered by, before the riffs kicked back in. Intricate instrumentation remains here, but it tends to stay tightly focused. 'Twinkler' serves as a subtle moment of reverie between the huge, hook-laden main event of 'Little Things' and the bass line driven stomp of 'Cocainium'.

'Back Where I Belong' sees the record take a tonal shift. The riffs die out, replaced with interlocking, delicate guitar licks and a vocal refrain which suggests bewilderment and resignation. 'Sea Lungs' is the sound of despair, Baizley's impassioned howl desperate to "find a way to breathe again", before Yellow closes out with the disharmonious grandeur of 'Eula', taking the disc from an opening full of triumph to an epic close full of tragedy.

The downplayed bass line of 'Board Up The House' affirms second disc Greens' determination to separate itself from the hard rock grandstanding of Yellow. 'Foolsong' and 'Collapse' rely on delicate intricacy for structure, Baizley's vocals taking on a removed, dreamlike quality on each haunting, sombre track. Closer 'If I Forget Thee, Lowcountry' does nothing to lighten to the mood or pick up the pace, ending Green with a reflective instrumental that adds a hitherto unseen sadness to the nostalgic feelings that Baroness' music has always evoked.

It would be lazy to consider Yellow the main album and Green the afterthought. The two work together to showcase the fact that the Baroness of 2012 have toned down the heavy metal volume and intensity, and worked hard to craft a structured, mature piece of work. Whether this is a good or a bad thing depends entirely on personal taste. To the wider rock world, Yellow/Green deserves to be regarded as a left of field classic, whilst to the metalheads who were perfectly content with the Baroness sound as it was, the record may seem something of a disappointment, its straightforward and melodic approach to songwriting the antithesis of the labyrinthine complexities and huge riffs of old. With this element conspicuously absent, it is difficult not to acknowledge a nagging feeling that something is missing, lost in translation.

Fundamentally it is important to judge the band on what they are, and not what they were or might be. Yellow/Green is the work of a band confident enough to experiment with contrast and melody within a set of more traditionally composed songs. There is still heaviness, but it comes from the themes and emotional overtones that the songs so effectively work with. If they had released an album that echoed previous achievements they may have been accused of stagnation. What they have chosen to do instead is broaden their horizons. This adventurous spirit is, above all things, the hallmark of a great band.