Toil and triumph characterised the last album from Finnish instrumental momentum rockers Siinai. Olympic Games traded exclusively and beautifully on the idea that hard work reaps great rewards, not only in the Greek tradition it celebrated, but also in the way they made the record sound. Long periods of seemingly aimless synthesiser mulch would gradually, gloriously erupt into a winners' refrain as the finish line came into sight. Time and time again, physical exertion was followed by deep relief and joy. As a dynamic template for an album, it was pretty unbeatable.

It's noteworthy, then, that for the album that follows it, Siinai have decided upon a synthetic hub of monotony - the supermarket. Somewhere people only go because they have to. No triumph, just toil (unless successfully beeping through vine tomatoes as salad tomatoes on the self-checkout counts as a triumph). Siinai's approach is understandably smaller and darker here, as they explore the world of the freezer aisle and that bit where they put all the broken stuff and let you have it for cheap if you're there after rush-hour. But the key thing is that they don't hate the supermarket. If anything, Siinai's supermarket is more a Vangelis consumer wonderland than a George Romero irony-fest with fat zombies clawing at the produce. 

As an example of simply conjuring images with music, Supermarket is splendidly accomplished. Artificial lights seem to burn from above at all times while you listen and there are even warped, tinkling, Supermarket Sweep-style checkout noises in the keyboards on 'Smiling Cashier'. There's a dark and relentless monotony to so many of the melodies - a monotony that slows any semblance of a tune to a crawl so laborious that you won't be able to hum them to yourself. But that's the whole point, really.

It's almost impossible for music to convey that monotony without itself being monotonous, but the real challenge is in then making it interesting. Siinai manage this by folding in the occasional expertly-positioned sound detail. 'Smiling Cashier' not only features those checkout beeps, it also deploys a terrifying synthesised, repeated yelp. Is it a seal croaking? A dog barking? In my head, it's the face of the cashier smiling laconically as he laughs in slow motion, features gorily peeling from his face while he gradually slumps forward onto the conveyer belt, where nets of Babybels have started to pile up. But that's just me. 

There's wordless wonder in the group chanting in 'Aeiouyäö', delicate, triplet-y lolloping in 'Prisma' and shimmery, up-front motorik bass in 'Shopping Trance' - all these elements delight at various points throughout Supermarket, chiefly to give the impression that within mundanity can indeed be all manner of intricacy. A plasticised life of rifling through vacuum-sealed packaging and corrugated tins of food far from their original source doesn't have to be depressing. In fact, the only time Siinai take their intentional, perfectly justifiable musical monotony to an extreme to make any kind of point is in 'Jonotus / Queue', which is more lush and tranquil than mind-numbing.

There are infinite wry charms to be found in Siinai's Supermarket. And, where previous works have found them painting in broader strokes (the aforementioned Olympic Games and a superb, tense and deeply dramatic collaborative LP with Spencer Krug), they've managed to turn the narrowness of the concept into a virtue. Like an aimless post-work meander into Tesco Extra that turned into a psychotropic slow-motion skip through a gaudy consumer heaven where everything's 30p less than normal, it's far more enjoyable and rewarding than it probably should be.