This really should be Stornoway’s moment to shine. When the band's delicate and introspective melodies emerged on the live scene in 2009, few could have imagined the emergence of folk-rock and its modern tributaries as a Grammy and Brits winning genre. But the world of music has a continually peculiar slant to its vagaries and as such, a band who started out with nothing but instruments, big hearts and a swish of gorgeous melancholy to their name now have the unexpected opportunity to make themselves a household name. If Mumford & Sons can conquer the planet, there theoretically should be no reason why Stornoway – a band with a far broader and more lustrous palate - shouldn’t be able to make serious inroads with their second record.

Now Stornoway are not Mumford & Sons, and as such, no further comparisons shall be made. The relevance of the comment lies in how Tales from Terra Firma often appears to be hunting out the mainstream in its carefree ambience, jaunty calls and big, bold choruses with a cocked eye on daytime radio playlists. But combined with a lack of building on their undoubted strengths, this kick towards the mainstream results in the record ultimately coming across as an uneasy truce between newer commercial aspirations and older artistic principles. Nobody wins, nobody loses, nobody is entirely satisfied with the eventual outcome.

From the opening organ, restless acoustic strums, responding trumpet and tumbling couplets of ‘You Take Me as I Am’, it becomes clear that Stornoway are laying out the scaffolding for a more prominent musical reach. And on those occasions where they manage to temper their loftier ambitions with caution and sensitivity, they can still sound delectable. The hushed melodies and understated mystery of ‘Farewell Appalachia’ are by equal measures glacially intoxicating and threatening. And the swirling psychedelia of ‘Hook, Line, Sinker’ comes as an unexpected marvel midway through the record: full of churning rhythms and dark counterpoints. It’s a new approach for them, and one that unexpectedly suits their predilection for driftwood undertow mystery. Barry Briggs – as ever – remains a wonderfully beguiling singer; making the record his own by veering between joyful, childlike exhalations and deep, introspective sighs and metaphorical ruminations on the changing nature of his internal and external worlds.

But for each positive, there’s another song that simply doesn’t hit the target, or simply runs out of space trying to sight its aim. ‘The Bigger Picture’, despite its sweet melodies and minor-key slants, seems simply an exercise in throwing as many disparate elements together and hoping they attain status, whereas the actually result is frothy and saccharine.

‘Knock me on the Head’ is woefully misguided and misplaced, both musically and lyrically. Promising wisdom and thrills, it ends up delivering banal couplets and an incoherent collection of ideas before ending in a bemused and clumsy full stop. And then there is the three-song closing salvo: ‘The Great Procrastinator’, ‘The Ones We Hurt the Most’ and ‘November Song’. Which again, are sumptuous and frustrating in equal measures.

There is much to admire about the teasingly slow build and ghostly Syd Barrett conclusion to ‘The Great Procrastinator’ but it ends up suspended agonisingly between a huge, dramatic climax and a cathartic understatement; which is the same that can also be said for the dream-laden and fog draped tapestry that is ‘The Ones We Hurt the Most’. Uncertainty is present just that little bit too often to fully satisfy. And while it would be unfair to solely blame this on their decision to self-produce the album, you can’t help thinking that a more assertive external hand may have honed some of the songs and defined their inner yearnings with sharper clarity.

As ethereally pretty and delectable as Stornoway’s seashell frequencies are, it’s always been tempting to suggest that they’re lacking that final element. And so it goes with Tales from Terra Firma. Only this time, they’ve overshot rather than undershot their aspirations. They may still be finding their way but from a purely objective standpoint, by album two you are expecting that bit more from a band: that hint of true growth and progression with the foot firmly fixing to the next rung on the ladder. Here, Stornoway are simply treading water; albeit in a larger and more colourful pool.

For all its many laudable attributes, Tales from Terra Firma proves ultimately frustrating: a skilled, capable and talented band still unaware of how best to channel and control their creative energies.