If Knots was an album of classical music it might be called 'Variations'. Sons of Noel and Adrian has, with this new LP, produced something which augments a central idea; emotionally and structurally the songs offer the same feeling successively and the album doesn't 'progress' so much as offer several perspectives on a theme.

Musically speaking, that theme is thick, layered and strangely intense. The album begins with 'The Yard', on which the opening guitar, picked and melancholy, several fluttering, lush orchestral instruments and half-wailed male and female duetted vocals combine over a low, dull, thumping and rolling set of drums, to the effect that the track plays out as one heavy texture.

That texture and that sense of monolithic sound is key to the album, and ones of its peculiar strengths. For a folk album, Knots is oddly weighty. 'Jellyfish Bloom', 'Black Side of the River' and 'Matthew' share that sense with 'The Yard'; other tracks, such as the beautiful 'Come Run Fun Stella Baby Mother of the World' and 'Cathy Come Home' present an alternation of it.

Without making claims for what exactly that weightiness attests to, its aesthetic, combined with the sense that each of the tracks here presents variations on it, has the effect of being able to draw lines between parts of tracks in order to divide the album in a number of different ways.

For example fourth track 'Big Bad Bold', which begins with the same picked guitar that opens a number of the tracks on Knots: its alternation between a quiet, wistful singing ('Meet me by the river…') and an almost frenzied, muddled loud section could easily be appended to track three, 'Jellyfish Bloom'. It could, as a result of the repetition of that 'Meet me by the river' section, almost be broken down into four separate songs itself. Knots is not an album which works in distinct sections; instead, to use painting as an analogy, it washes out as one hue.

That's not a bad thing at all: to go with the 'variations' idea, it really strengthens it by bringing to light new emotions and outcomes as a result of its treating, over and again, the same musical material.

Indeed, just as the album could be divided in the ear of a listener in a different way than Sons of Noel and Adrian have chosen to divide it, it is probably better to say that it shouldn't be divided at all. It works better as one shade of colour on one canvas; like a plasma globe that, once you put your hand to it, shoots off from its centre several branches of the same material.

And Knots does feel electric, in a way. A super album.