“I need some fine wine and you, you need to be nicer.” Not my words (although it would have made a number of drawn-out breakups a lot more efficient if they had been), but a band that, for the sake of a provocative headline, I am going to name as the greatest emo band of all time: the Cardigans. And there’s nary a downtuned chord, fringe, or Sesame Street backpack in sight. Stay with me.

There’s an idea that before the Cardigans’ latter-period countrified melancholia, the band was an exercise in indie whimsy, that when they emerged from Jönköping in the south of Sweden, they tended towards sickly to the point of nauseating. Yes, some of that is true – their first album was called Emmerdale, after all – so much so that it’s easy to be blinded to the plain fact that the song that broke them in the UK was called Sick and Tired. There was always a panic cloaked in fluff that would make them irresistible to students of sad Swedish pop. And Sweden is excellent at sad Swedish pop.

Consider their biggest hit, powered by its inclusion on the soundtrack to Baz Luhrmann’s Romeo + Juliet, Lovefool. Its premise – “Tell me you love me; I don’t really need to believe it, I just need to hear it” – is unutterably bleak. Again, that can be easy to overlook when faced with the memory of the band guest-starring as themselves to play the song on a 1997 episode of Beverley Hills 90210. (For us sad Swedes fixated on 90s American high schools, that’s enough to elevate them to cult-hero status in itself.)

The reason for the unlikely epithet that I’m going to stand by, at least until the end of this article, is their 2003 masterwork, Long Gone Before Daylight. Reinvented after five years’ absence, the band were now a dark, understated country-pop outfit, Nina Persson dying her hair black to underline the point. There might have been a sadder record made this century, but I’m at pains to think what it is.

The strength of that album was lost amid that period’s surge of superior Scandinavian rock, and so the Cardigans were regarded largely with critical disdain. Reviewing the album for NME, Peter Robinson wrote: “If we’re honest with ourselves, the threat of a new Cardigans opus has hardly had the world on the edge of its collective record-buying seat. Even tales of an all-encompassing Swedish new rock supergroup – Pelle from the Hives, Ebbot from Soundtrack of Our Lives and Nicke Hellacopter all show up at various points – has had difficulty raising a solitary eyebrow. And if you can say anything for the Cardigans, it’s that they’re good at eyebrows.” In the end, though – despite himself, you suspect – he called it “an album powered by its own radiance”, and awarded it eight out of 10.

What lifts Long Gone Before Daylight up – or, rather, down – is its feeling of resignation, not the easiest emotion to illustrate within the dynamic medium of popular song. But that’s the deadpan skill Nina Persson injects into her lyrics and guitarist Peter Svensson into his melodic constructions.

“For 27 years, I’ve been trying to believe and confide in different people I’ve found,” she sings, opening the album with Communication. A single line says everything about the pre-30 panic of not yet having it all or making sense of the world, or even knowing who you are yet. If growing up is the process of coming to realise how much you don’t know about anything, then Communication is its most potent anthem.

Yet there are darker insights to come. The ever-so-slightly more breezy You’re the Storm sees the singer cast herself as a country that needs conquering. Whether she’s playing a character or not, these are not the words of an empowered woman, and it breaks your heart. Darker still, And Then You Kissed Me, a sort of inversion of the Crystals’ He Hit Me (and It Felt Like a Kiss), has to be the tenderest song about an abusive relationship, with Persson at one point inflicting on herself what would come to be known as victim blaming: “It struck me that love is a sport, so I pushed you a little bit more.” And all the while you’re never entirely sure whether the whole thing is a metaphor.

Similar body-horror seeps into Couldn’t Care Less: “My hands don’t work like before / I shiver round and scrape at your door / My heart can’t carry much more.” Please Sister asks with blank-eyed curiosity: “So if it’s true that love will never die, then why do the lovers work so hard to stay alive?” Even the gentle declaration of love on the lead single For What It’s Worth is prefaced with the song’s title. The perkier Live and Learn appears to offer some respite and resolution, before the sting in its tail: “I came to on a corner, want some help from a man, and goddam I don’t seem to have learned that a lady in need is guilty indeed; so I paid and got laid in return and I don’t know what I’ve learned.” Guilt, shame and resignation until the end.

The Cardigans would be back in 2005 with the marginally frothier Super Extra Gravity and the beaujolais that Persson was craving at the top of the page, but in Long Gone Before Daylight they created the anomaly that qualifies a platinum-selling pop group as cult heroes, and the greatest emo band there ever was. It’s my deranged assertion, and I’m sticking to it.