If you haven’t noticed, Arctic Monkeys have come a long way since the nightclub queue-jumping high-jinks of their debut album, Whatever You Say I Am, That’s What I’m Not, 12 years ago. Alex Turner and Matt Helders now live in LA, and are unabashed about their love of the continent’s indulgences – but this has not been accepted by a lot of their early fanbase. Their first two albums were so entrenched in British teenagehood, that when they turned into Yankees with the Josh Homme-assisted third album Humbug, it threw their audience for a loop – some of whom never caught hold of them ever again. And, never ones to turn back, Arctic Monkeys forged ahead with their affinity for Americana; putting out the R&B-influenced AM in 2013.

Anybody who has fallen out with Arctic Monkeys over their adoption of the culture of our brothers across the pond are unlikely to find their way back on board with album number six, Tranquility Base Hotel & Casino. It’s a bold about-face by the Yorkshire lads, one which sees them switching their main mode of attack from guitar to piano, which might throw a spanner in the works for anyone listening out for future festival anthems. The album is also one that could not have been created without the overarching influence of America’s indulgence and adoration for modernity, celebrity and image. While the official story of the concept behind the album is that it’s centred around a future colony of humans on the moon, it’s pretty clear that the various characters at the assortment of soirées that populate the album are inspired directly by Turner’s time in Hollywood. After all, as a lad from the Sheffield suburbs who probably thought “taqueria” was a cheap Spanish lager for the majority of his life, sitting at a gifted Steinway grand piano in a spare bedroom-come-practice-room overlooking the Hollywood Hills, he probably did feel a bit like he was on the lunar surface.

The different personas that inhabit Tranquility Base Hotel & Casino are all high-rollers in one form or another – after all, you’d have to be in order to make it to the moon – but they’re usually dissatisfied. We’re introduced to the album, and Arctic Monkeys’ new interstellar sound, via ‘Star Treatment’. It’s a song told from the point of view of an artist-in-residence at the plush new facility, who’s looking out over the deluxe components of his life and yet is teetering on the brink of self-destruction. With a fluttering bass line and twinkling piano, Arctic Monkeys paint a picture of a life lived in snatches, with plenty of alcohol and modern gadgetry, but with a desire for a deeper connection, when all they get is inane talk at yet another cocktail party full of strangers (“what do you mean you’ve never seen Blade Runner?”).

These disgruntled and shallow people abound in the following tracks. ‘One Point Perspective’ is jaunty piano pop, characterising the central figure as a guy who has made good and thinks he’s on top of the world because all the options are open to him at this point - whether he wants to run for office or be in a cover band. He feels part of the industry, telling anyone who’ll listen about a documentary he saw and boasting about driving around listening to the score. Turner plays this persona dead straight, and allows us to see the hollowness of it all, especially as he’s constantly losing his train thought, probably after a few too many prescription meds. We shift to next-door on the following track ‘American Sports’, where a similarly well-off inhabitant is sitting alone and stewing on how having all of his deepest desires fulfilled has not satisfied him whatsoever; a swashbuckling piano line and atmospheric guitars bringing his inner darkness to life. ‘Golden Trunks’ seems like the result of an all-night writing session spent drinking behind a piano bench and in front of the 24-hour news cycle, with warped images of Donald Trump and drunken confessions of love getting mixed up together. This is saved from complete self-indulgence by a particularly James Bond theme-esque guitar, piano and vocal take, giving it a cartoonish swagger. ‘Batphone’ is steeped in cinematic imagery, as it focuses on a successful figure who just released his own fragrance, but still sits at home alone at night in his massive mansion watching art films like the Vengeance Trilogy, waiting for someone to call. His self-obsessed loneliness is rendered expertly in grey shades by Arctic Monkeys’ vamping organs and creeping rhythm.

Tranquility Base Hotel & Casino is at its best when the indulgences and luxuries of the setting are celebrated. The title track is central to this, as we take on the perspective of the receptionist of the hotel. From this vantage point we see all sorts of characters and scenes, from Jesus in the day spa to someone admitting that technological advances turn them on. While the chorus “Tranquility Base Hotel & casino, Mark speaking, please tell me how I may direct your call” might read as cumbersome, the way Turner savours the words in his mouth makes it a winner, and you can imagine the camera scanning across the plush lobby of this establishment, picking out all the various celebrities and beautiful people flouncing around. ‘Four Out Of Five’ is the swinging standout from the album, with bouncing chords and Turner grandly and gregariously inviting us to go and stay with him on the moon, which is never a clearer analogue for LA than when he tells us “it’s such an easy flight” and that “cute little places keep on popping up.” He has even opened his own taqueria called The Information Action Ratio, which has been getting rave reviews; “four stars out of five,” he sings in gleeful pomp, providing the biggest chorus on the album.

Other excursions on Tranquility Base Hotel & Casino include a dalliance with virtual reality (‘The World’s First Ever Monster Truck Front Flip’), a psychedelic voyage through experimental imagery (‘Science Fiction’) and unadulterated parties in celebrities’ manors (‘She Looks Like Fun’). However, much as the unending mores of Tranquility Base Hotel & Casino seem strangely dissatisfying to the people residing there, so too do these few songs. Without much of a hook to them, and even with Arctic Monkeys’ best attempts to turn them into the same kind of polished intergalactic vessels as the best of the songs on the album, they don’t manage to take off, and remain grounded and easily forgettable. The only other slight disappointment is that drummer Matt Helders never gets to fully unleash his primal force. However, the way that Nick O'Malley's loping bass and Jamie Cook's cinematic guitars boldly add depth to Turner's stories is unforetold in their indie rock past - and Helders is studious in his rhythms, if not stunning, and who knows what else he contributed to the swirling sounds on Tranquility Base.

The last affecting moment on Tranquility Base Hotel & Casino is the terrestrial final track ‘The Ultracheese’. In this sorrow-filled sign off, we find Turner inhabiting a character who can’t be far from his true self, thinking back on friends he left behind to come and follow his dreams. With a lazy oom-pa-pa gait, Turner brings his loneliness to the fore with major chords and a devastatingly aloof vocal, recalling simple scenes from his youth. It caps off Tranquility Hotel Base & Casino with a perfect coda to the collection of stories from this futuristic settlement.

Arctic Monkeys didn’t release any singles in the lead up to the release of Tranquility Base Hotel & Casino. On first listen it seemed obvious to me that they’d done this because there were no singles to be found on this mid-tempo, self-indulgent piano album. However, on subsequent listens it truly opened up and bared its subtle and plentiful delights, and it became clear that they hadn’t released an advance single because this is meant to be indulged in as a song suite, and those who do take the time to appreciate it as a whole collection will get the most of it. People will certainly be talking about Tranquility Base Hotel & Casino in the short term because of how much of a surprise it is, but it will be interesting to see how it will be talked about in the long-term; whether it will turn out to be a turning point in their careers or just an oddity in their catalogue. Nevertheless, it seems to suggest that Arctic Monkeys are a band with a longevity we might not have expected once upon a time, and they are continuing to build their sizeable legacy as they move on, more unpredictable than ever.