"What should I tell her? She's going to ask…" These words, murmured by frontman Greg Dulli over a slithering, tendril guitar line like a snare tightening around its prey, open Gentlemen, the third album by the Afghan Whigs. Part-confessional, part-boast, part-catharsis, the album is as bleak and unforgiving an examination of love, lust, addiction and oblivion as the 1990s ever delivered.

What, then, does Dulli tell "her", and also us? Only everything. Only every little black morsel of his heart, soul and groin. Only every little trick his brain knows to sell his ass to you, and how it feels the next morning, when he finds himself lying next to the latest victim of his narcotic charm, the harsh light of day leaving no scrap of cover for his shame and remorse.

I once asked Dulli how anyone could ever sleep with him again, having revealed every ugly part of himself across the tracks of Gentlemen.

He laughed. "That's exactly what my mother said."

Context isn't everything, but sometimes it's important. In 1993, the year of Gentlemen's birth, the grunge wave was peaking. Two years earlier, Nirvana's Nevermind had crashed into the mainstream, followed by a tsunami of weird, twisted and often wonderful underground noise, much of which was subsequently signed by major labels convinced that anything plaid, anything Seattle, anything "grungey" would similarly sell. Sometimes they were right. Over time, the style congealed somewhat, and a certain uniformity encroached: bands became generally long of hair with "interesting" beardage, and dressed like they'd been tarred and hurled into a shitty thrift-store. Don't mistake my honesty for arch cynicism: truly, these were great days.

But Afghan Whigs were different. Though previously signed to grunge's signature imprint, Sub Pop, they hailed from Cincinnati, not Seattle. Dulli might occasionally have sprouted a hideous, 'stache-less chin-beard as the era dictated, but he and his Whigs dressed sharp: shirts with collars, shoes you couldn't wear on a basketball court, and the general ambience they might have stepped out of the frame of a Tarantino movie. And while their guitars often stirred much angst, like an infernal tornado of turbulence, their frame of reference was crucially adrift from their labelmates. Because grunge was white as hell, the only Black in its sonic DNA being Flag or Sabbath. And then came the Whigs: their final Sub Pop release, 1992 covers EP Uptown Avondale, essayed tunes by Al Green and Percy Sledge, along with an acrid version of Freda Payne's Band Of Gold, and a take on The Supremes' 'Come See About Me'. This EP wasn't a one-off; included among the bonuses (bonii?) on this deluxe reissue of Gentlemen is a former B-Side, a live medley of The Supremes' 'My World Is Empty Without You' and 'I Hear A Symphony' that correctly identifies the songbook of Motown bards Holland/Dozier/Holland as some of the heaviest, darkest, most emotional tuneage in music, tales to make Swans sound like The 1910 Fruitgum Company, and to banish Sabbath's tales of "figure(s) in black" as so much juvenile nonsense compared to the terror, the agony of betrayal and a broken heart.

Afghan Whigs had soul, a quality that went deeper than their excellent taste in cover versions, seeping into Gentlemen in ways that went beyond the surface, beyond simple pastiche or homage. Only the penultimate 'I Keep Coming Back' – penned by Chicago producer/songwriter Leo Graham and originally cut by windy city singer Tyrone Davis in 1970 – makes any obvious soul moves, and the aching smoulder of Rick McCollum's guitar, the band's dignified crawl and Dulli's wounded croon (not always hitting the right notes but always nailing a truthful grain in his howl) combine to deliver a track that could hold its own on one of Dave Godin's Deep Soul compilations.

Gentlemen's lyric sheet also set the Whigs far apart from their era. Nirvana dealt in murkily surreal imagery and keenly remembered childhood angst; Soundgarden broke out of metaphoric rusty cages; Pearl Jam rhapsodised misunderstood and fucked-up kids. Dulli's tales, however, were blunter, darker, more adult. Gentlemen is an album about sex, and sometimes love; about the tangle, the aftermath, the gratification and then the recrimination. Romance, at least in any corny sense, is absent.

Most of all, Gentlemen is an album about Dulli, an unsentimental gaze into the mirror, and an exercise in reportage on what he finds there. There's an unflinching, unforgiving tendency at work here, one that recalls Sebadoh's Lou Barlow – perhaps an unlikely comparison, but an appropriate one. In addition to penning a sheaf of songs he once admitted existed purely to bully his wife into returning to him, on albums like Bakesale Barlow wrote "love" songs that unabashedly revealed his own neuroses and failures and faults and crimes, songs that could make him seem like an asshole, to a degree where you could only applaud his exacting honesty. Here, Dulli is playing a similar game: telling stories, telling truths, and perhaps discovering that actually he's the villain here.

"Love" in the world of Gentlemen is a twisted and complex and contradictory thing, and sometimes Dulli's purposefully evading it, in search of baser and more immediate pleasures. Be Sweet could be a signature song, of sorts. It's the calling card of some kind of pick-up artist, back before celebrity creep Neil Strauss and his book The Game swindled a generation of Fedora-sporting feebs into believing that winning a woman into your bed was as simple as executing some kind of carnal Nintendo Code, by performing a series of sociopathic and misogynistic tics like 'Negging' and 'Sarging'. A different generation of barhopper, Dulli's no better than these nerds really, admitting "I've got a dick for a brain/And my brain is gonna sell my ass to you". And that would be fine – sexual healing was a universal thing long before Marvin Gaye gave it a name – but there's a dishonesty to the transaction, an imbalance of the power-game. "She wants love," Dulli winces, "And I still want to fuck."

Love, it seems, is often the tarpit Dulli falls into while searching for something else, something simpler, and within those four letters lie his potential destruction. Imagery of drugs and addiction mingles with these pleasures of flesh: Dulli confesses he and his partner "shared a needle once or twice" in What Jail Is Like, in the same breath that he's howling that love is like incarceration, while on 'Fountain & Fairfax' drugs and alcohol are what he's given up in order to have his dream woman. But on the latter song, a woozy and menacing brawl named for a particularly sordid intersection in LA, this longing becomes a noir-ish torture of deceit and suspicion. "Angel, come closer, so the stink of your lies sinks into my memories… She said, 'Baby, forever'… But it's Tuesday now, I hear him breathing inside of her," Dulli growls, like Fred MacMurray in the final reels of 'Double Indemnity'. Cocksman thusly cuckolded, devil betrayed by his sweet angel, his only recourse is to punch the self-destruct button: "Let me drink, let me tie off."

Like any Catholic – good or bad, lapsed or not – Dulli knows his every sin will ultimately be punished, though sometimes he's his own hangman. On 'Debonair' he makes it explicit: "Tonight I go to Hell/For what I've done to you". This ain't no fire'n'brimstone fiction that he's burning in, but a more immediate, earthbound torture, and while he swears "this ain't about regret", the blackness of his actions poisons their hearts, their heads, their love, as he screams, like a man who thought he was somehow hitherto inoculated against that which is making him sick: "Baby, it's in our bed".

Villain. Victim. Sometimes these roles are transient. Sometimes they're non-exclusive. Sometimes you think you're one, and you wake up to find you're the other.

Text is important, but it's not everything. Beyond those words that Dulli howls, the music of Gentlemen is remarkable, and again marks a potent distance from their contemporaries. Their previous album, 1992's Congregation, had sketched out those soulful influences Uptown Avondale would make explicit, eschewing the Stoogey/Sabbathy ruts of their Sub Pop labelmates for a songcraft of a more classic vintage, boiled down to a bone-simple, brawny immediacy. Gentlemen shades in that spareness with piano, slide-guitar and occasional strings, fleshing out the canvas with subtle but powerful results.

The Whigs' deftness, their shape-shifting power, impresses throughout. 'Be Sweet' switches from keening ballad to full-throated, furnace-fierce roar with a vicious grace, embodying the song's Jekyll and Hyde contortions. On Gentlemen, over drums seemingly lifted from a fleet-footed, villainous funk, the guitars swell and squall like a storm, notes bent into bruises and strings strangled into something ugly enough to match Dulli's self-tortured soul. On 'Debonair', they snap and crackle a detuned chicken-scratch lick, stirring up a malevolent funk; on 'When We Two Parted', they swoon in opiated gloom, matching the dead-end misery of the lyrics; on 'Now You Know', they lash out a devil-driven, Zep-ish blues riff, the rhythm section in the pocket and pounding out a tight-but-loose, 'When The Levee Breaks' heaviosity. Check out the demo version, delivered sans vocals, and you can hear hand-claps in among the primordial riffage and pungent vibe.

The demos themselves, while manna for nerds like oneself, are for the most part hardly revelatory: dry run-throughs that rarely differ from the finished versions save for the absence of the occasional scything cello, or any drums on the old testament churn of climactic instrumental 'Closing Prayer', they mostly serve to underscore how the embellishment of the finished tracks raises Gentlemen from magnificent to masterpiece. The vocals don't quite hit the spot so well on the demos either; clearly, those master takes used on the album are the proverbial lightning-in-a-bottle, Dulli summoning performances he'd never match again. His vocals on the title track are astonishing – corpse-painted feebs fumbling with matches and lighter-fluid in cathedral car-parks should cop an ear to Dulli hollering "Understand, I'm a gentle man" with such oleaginous bile, a cold-sweat manifestation of dark truthfulness, or truthful darkness, and know what true terror sounds like.

It's notable, then, that Dulli doesn't sing on Gentlemen's finest track, instead handing the microphone to Marcy Mays, singer with fellow Ohio group Scrawl (whose 'Ready' is covered by the Whigs on the bonus disc), for 'My Curse'. A country-blues eked out on busted acoustic, doleful piano, restrained percussion and choked slide, blossoming into great broken crescendos on its choruses, it's the most explicit expression of love-as-sadomasochism, a theme that underpins the entire album. "Ooh, hurt me baby," purrs Mays, her voice cracked and raw; "I flinch so when you do." It's said Dulli invited Mays to deliver the song as he couldn't face singing it himself; he performs the demo version, but Mays' take is far superior, vulnerable but powerful.

"I do not fear you," she announces, but the lyrics conjure a violence between the lovers, a volatile chemistry that only finds peaceful expression when "I came undressed". The song captures Gentlemen at its most troubling, and also its most erotic, Mays blurring the line between pain and pleasure, unable to find any resolution to the conflict with her partner, but embracing it, agonies and all, as an ongoing continuum, whatever the cost. "There's blood on my teeth/when I bite my tongue to speak," she sings, before swinging again to the sexual: "Zip me down/Kiss me there".

Dysfunction, it seems, is still a function, and the fucked-up world of Gentlemen is very much a "whatever works"-ocracy, where it is what it is. The song, like the album, is ugly and dark, sad and beautiful, bruised and empowered; a portrait of conflict and complexity painted in 50 shades of the blues.

Afghan Whigs would follow Gentlemen three years later with a more ambitious but less satisfying opus, Black Love, and 1998's 1965, their most accessible album yet, which nevertheless prefigured their split. Recently they reformed, delivering a comeback album, last year's Do To The Beast, which in no way dishonoured that which had come before. In the interim, Dulli formed a new outfit, The Twilight Singers, though their subject matter, and their soulful, dark music, was strongly familiar.

None of that ever bested Gentlemen, however, a singular album in both intent and execution, and the most satisfying expression of Dulli's dark, dark heart. The grunge era's answer to Millie Jackson's Caught Up, it remains a triumph, an album whose impact is no less powerfully felt 21 years on.