In a lovely 1963 piece on Miles Davis, Kenneth Tynan quoted Cocteau to illuminate the art of his ‘discreet, elliptical’ subject: Davis was one of those 20th-century artists who had found ‘a simple way of saying very complicated things’. Jump to 1966 and the meatier, beatier sound of a UK Top 20 hit, the Who’s ‘Substitute’, a vexed, stuttering anti-manifesto, with its self-accusatory boast: ‘The simple things you see are all complicated!’ You couldn’t find two more different musical cries: Davis’s liquid tone is hurt, steely, recessive, where Townshend’s is upfront, impatient, hectoring. One arrow points in, the other out. But somewhere in the journey from one to the other, from cool, cruel blue to Townshend’s three-minute psychodrama – ‘I look all white/but my dad was black’ – was the brief, paradoxical flare of Mod: the story of how a small cabal of British jazz obsessives conducting a besotted affair with the style arcana of Europe and America somehow became an army of scooter-borne rock fans, draped in the ambiguous insignia of RAF targets and Union Jacks.

What Richard Weight calls the ‘very British style’ of Mod found its initial foothold in late 1950s Soho with the arrival of the jazz ‘modernists’, who defined themselves in strict opposition to the reigning gatekeepers of Trad. Modernists were wilfully brittle, stylish, working-class Cains, different in every way from the whoop-it-up trad jazz Abels. Trad – hugely and improbably popular in its day – had a predominantly middle to upper-class and purposively vulgar fanbase. In its ranks were Kingsley Amis, Philip Larkin and George Melly, who all later wrote of this time as of a lost Eden. Larkin’s jazz column for the Telegraph ran from 1961 to 1968, a period roughly coextensive with Mod’s quiet rise and noisy fall.

Trads embraced a louche, boho scruffiness (silly hats, sloppy jumpers, duffle coats), where Mods dressed with considered exactness. Trads were British to a fault (real ale, CND, the Goons) while the Mods had a magpie eye for European style, from the Tour de France to the Nouvelle Vague. Trads followed Acker Bilk, Mods worshipped Thelonious Monk: even at fifty years’ remove, you can see how sharing the same club, city or country might have been problematic. If the Oxbridgey Trads had a philosophical pin-up it was Bertrand Russell, with Freddie Ayer for real deep kicks; Mods backed the darker horse of existentialism. How much the Mod crush on continental philosophy was a pose, and how much serious engagement, is a moot point. Even as ‘mere’ pose it’s a very interesting one. In the dourly socialist cinema of the British New Wave, working-class characters are portrayed as sooty beasts of burden, life-force bruisers, 12 pints a night men; Camus-rifling aesthetes are thin on the cobbled ground.

Trad appealed to folk who were more or less content with the way things were along a certain squeaky corridor of Englishness. Mods felt an obscure pinch of agita at the thought of what their future promised. American jazz and European movies weren’t just crib sheets for how to wear loafers and a cravat, they were permission slips that allowed their audiences to pause and reflect. Trad reactionaries and Mod wideboys? Doubtless it was never quite so cut and dried. Skim the sub rosa lit of the time (Robin Cook, Alexander Baron, Colin MacInnes) and you’re plunged into a lost river with discrete but commingled tributaries: gay, criminal, East End Jewish, upper-class drop-out, lower-class dandy; the ‘morries’ of Cook’s dodgy Chelsea set, and Baron’s Harryboy Boas, a proto-Mod. ‘One thing about me, I always dress smartly,’ Boas declares. ‘A good suit, midnight blue mohair, this year’s cut. Dazzling white shirt, quiet tie of silk, rust-colour. Buy your clothes good if you have to starve afterwards.’

Weight devotes as little space to the early ‘modernist’ period as he can get away with. Movements of thought are, admittedly, harder to track than fashionable hemlines, but he seems palpably incurious about this smudgy horizon. Sartre gets a single sentence referencing his ‘famous dictum that “One must act to be free.”’ Hang about – is that his famous dictum? I’m a bit hazy after forty years, but off the top of my head (current haircut modelled after the sleeve of Chet Baker & Crew, Pacific Records, 1956) wasn’t it ‘Existence precedes essence’? Or: ‘Man is condemned to be free’? Or (surely a contender for a TV quiz show clincher): ‘Hell is … other people!’? I fed the ‘famous dictum’ into Google and it was nowhere to be found (Weight supplies no attribution). Existentialism likewise gets a single … oh, wait, it’s the same sentence as Sartre. They share a sentence. Halvsies. (You’d think Weight might at least have mentioned Sartre’s Mod-like appetite for amphetamines; if ever a novel read like one long comedown from a teeth-grinding high, it’s Nausea.)

Further down the road, Mod became more about buying the right records and wearing the approved uniform, but in the nervy modernist dawn there was a real hunger for films, books, dialogue; or as Weight puts it in the first subheading of his introduction: ‘Amphetamines, Jean-Paul Sartre and John Lee Hooker’. Which is a nice phrase, even if it’s half-inched from an interviewee in a previous book, Jonathon Green’s flawless oral history of 1960s counterculture, Days in the Life. (In fact Green also used it as a subheading. This feels a bit previous to me: to use someone else’s quote is OK, but their layout too?) The early Mods were navigators, Magellans of the postwar field of leisure time, which had to be imagined, cast in this or that shape. Everything was up for grabs: music and clothes, sex and sexuality; the speech and language of put-down and put-on and pop fandom; transport and travel; nights out and nights in. Everything, in fact, we now take for granted as ‘youth culture’. It was a heady time of redefinition; but we also get the first migraine flash of a paradox that would split Mod, and define other subcultures: what began as a principled refusal of the nine-to-five wage-slave grind found its most vivid street-level expression in avid consumerism. As Peter Gay put it, paraphrasing Walter Gropius: ‘The cure for the ills of modernity is more, and the right kind, of modernity.’ This could be Mod speaking.

Gay’s reflection is from his 1968 book Weimar Culture, and its subtitle is also applicable here: The Outsider as Insider. The tension between wanting to be unique but needing to belong underlies all subcultures. For the Mods, as with the Situationists (awol from Weight’s index), there was a conflict between rowdy group identity and individual slant. They mixed outdoor jaunt with indoor dissipation, group jamboree with sombre reflection, and they took very small things very seriously indeed, things other people wrongly perceived as frivolous. The Mod obsession with Blue Note album sleeves and Italian fashion had the quality of fetish, in both the Marxist and ritual senses. It required near-fanatical commitment to ‘source’ the materials required for a makeover. (In the early 1970s when I was a teenager, the high street was still hopeless, a fashion desert: Are You Being Served? was as much social realism as ribald sitcom.) Early Mod shared with Bauhaus an almost puritan obsession with clean style and correct design. Early Mods had a deserved rep for sartorial aloofness, which shaded into a kind of radiant anonymity. Like the ‘man of the crowd’ in Baudelaire (and Benjamin) they were in the crowd but not of it, tracking sociability like spooks instead of being haplessly caught up in it like everyone else.

Early Mods could ‘pass’ between work and play without changing their suits, which is perhaps one of the reasons they were never sent up in the culture at large. Think back to 1960s and 1970s low comedy: no TV sketch show or sitcom or kitschy horror film was complete without its parade of subcult Aunt Sallies – hippies, ton-up boys, skinheads, punks. Rockers had shivs, skinheads had bovver boots, hippies might dose you – what was a Mod going to do? Make you listen to Otis Redding? Force you to buy a decent pair of trousers? Mods posed a far less obvious threat. They flew the Union Jack, after all, and most of them had jobs; they were clean, well turned-out and had nice haircuts. In 1964 there was a brief spasm of tabloid outrage over some rather tame skirmishes between Mods and Rockers, mostly conducted in bracing seaside ozone. Talk of scooter-borne ‘vermin’ aside, the real fear may have had less to do with physical aggro and more to do with the difficulty of slotting Mod into any obvious class or subcult genealogy. (Even the word ‘subculture’ suggests soil, shadow, dirt; airless oubliettes; greasy rungs leading down into a Harry Lime exile.)

Class plays through this story in sighing counterpoint, but Weight has the pop sociological equivalent of a tin ear. He relies entirely on secondary research, on other people’s now exaggerated accounts of already faded memories, and has zero feeling for real lives, real voices, real flight and fall. There is a dusty old pub-table anecdote about some Mod who would only have bunk-up sex if there was a trouser press to hand for his strides – which is presumably meant as a dig at Mod’s twisted priorities. (Full disclosure: no trouser press, but I do own two pairs of antique shoe trees.) Another way to see this tale: having saved for months to afford a gorgeous suit, and probably unable to afford a replacement any time soon, you’re going to make damned sure it lasts. Maybe this guy was on a 48-hour weekender and didn’t want to roll into work on Monday morning looking like an undignified mess?

Still, Weight’s basic thesis seems unexceptionable: Mod as the beginning of everything we now take for granted in style culture, the ‘DNA of British youth culture, leaving its mark on glam and Northern Soul, punk and Two Tone, Britpop and rave’. But DNA is one thing, ‘leaving a mark’ quite another. Was Mod central and catalytic, or peripheral and intermittent? Because Mod itself came to signify so many different things to so many different people, and because Weight fails to separate out and clearly define words like ‘dandy’ and ‘modern’ and ‘modernist’, following his argument can be like trying to see a line of pebbles under a bank of fog. He treats wildly dissimilar phenomena – Mods, dandies, dandy Mods and modernist dandies – as though they were the same thing. (Even at the time, many original modernists spurned Mod as a moody knock-off, a Carnaby Street caricature – wayward ideas replaced by winking insignia and a price tag on everything.)

Weight is so stuck on his through-line map that he never stays long enough to see the strangeness of the scenes he’s passing through. (I’m tempted here by the neologism ‘tellyology’. Definition: shaping history with both eyes on a potential TV series.) I suspect the book he really wanted to write was a social history of Britain as seen through its subcultures, but these days books need hooks, and that’s where Mod comes in. Or rather, where Mod goes out, because rather than looking again at the rich and paradoxical details of each mod-ish stage, Weight is always pushing on to the next ‘Mod-influenced’ or ‘Mod favourite’ thing, from ‘Golden Egg restaurants’ to the ‘Mod-inflected British rock group Kaiser Chiefs’. The links can be tenuous, to say the least. Jean-Luc Godard gets in for A Bout de souffle. OK, but Weight makes it sound like Summer Holiday with Gitanes and avant-garde haircuts. Alain Delon gets two mentions – one for a Smiths sleeve, the other for being an early scooter adopter. (None for his revenant gangster in Melville’s Le Samouraï, which may be the most Mod film ever made: narcissism as narcotic, style as armour, and a fatal crush on a young black nightclub singer.) The ‘beautifully dressed’ Marcello Mastroianni makes the cut, because he ‘embodied the modern, urban European male in films like Fellini’s La Dolce Vita and Antonioni’s La Notte’. You’d think these films were a freewheeling wolf-whistle breeze, when in fact their ‘modern, urban European male’ is flesh-spoiled, jagged with anomie, lagging behind his own heartbeat. He may be sharply dressed but he’s losing traction. Weight’s tick ’em off method makes everything sound like fashion PR: he catches the surface glimmer but misses any warning flares about imminent decadence. He honours some arthouse films because they were one of the ways Mods ‘absorbed … the Continental lifestyle’. I’d like to have heard more from ex-Mods, in their own words, about the honeymoon experience of seeing such odd, uneasy films. (Weight takes one quote from Terry Rawlings’s book Mod: A Very British Phenomenon. Hmmm, catchy title, what?) By stressing fashion over ideas, Weight sacrifices an important thread: he makes young working-class Mods sound like boys who will cross an entire continent for the right pair of socks, but don’t have an idea in their heads.

The Beatles’ crucial role in the American Invasion of the mid-1960s becomes ‘the mediation of Mod-related music and fashion to young Americans’. The Kinks are duly ticked off as a Mod band (in Weightese, ‘figureheads who in their music, dress and interviews articulated Mods’ outlook’) when they were never really Mods, or hippies or anything very easy to pin down. What they were was awfully odd from the get-go, their echoic lack of definition precisely why they were so singular at the time and still sound so convulsively fresh today. If Ray Davies was a Mod, it was only one of many pre-emptive masks he sported. (And ‘sported’ is definitely the word.) The Union Jack draped around the Kinks was thorny collage not breezy appliqué. Beneath the lilt and fizz of the group’s sound, Davies’s fashion slaves and ladies’ men are a dodgy lot, North London stand-ins for Mastroianni’s self-hypnotised Casanova. In ‘Dandy’ the larky bedhopper is sent up, then stripped to pieces. But what’s really nagging at Davies here is the passage of time: ‘You lowdown dandy, you can’t escape the past/Are you feeling old now?’ Davies already had a ticcy eye on the clock. Success had no sooner spread its gold lamé legs for him than he was pouting: ‘Where have all the good times gone?’ He sounds tired of waiting but truly petrified of the uncertain fate at waiting’s end.

I spent a recent coastal holiday listening to the Kinks’ back catalogue and was mesmerised all over again. (I wanted to do the same with the Who, but all I found in the motorway services’ rack was an audiobook of Pete Townshend reading his recent autobiography: a whole 15 CDs’ worth. I’m sorry – no one, not even a freelancer, has that much leisure time.) A half-century on, it’s difficult to recapture the tingly shock of Davies’s quicksilver voice in its original context, but that still doesn’t explain or excuse how the Kinks, like Mod, are being turned into a paisley signifier for reassuring nostalgia. There’s a whole other story here but Weight can’t, or won’t, hear it. For one thing, he needs to hurry along to match the Kinks up with mid-1990s Britpop. We don’t ever learn if the similarity goes very deep, but it’s one of those now obligatory pop-heritage coach stops. It has to be said (except Weight doesn’t say it) that Blur’s ‘Country House’ already sounds more dated than anything from a sunny afternoon in 1966. But here they all are, stirred into the same pot: the Who, the Kinks, Blur, Oasis. Here’s ‘Noel Gallagher playing his trademark guitar’, the word ‘trademark’ an unhappy, if telling, choice. Here’s a photo of Blur where they ‘display their Mod influences in Clacton in 1993’. Though some of the 1960s groups doubtless spent happy time in Clacton as kids, it’s unlikely that Blur had ever set foot there before this stagey photo op with an ‘iconic’ white Jag. As for any display of Mod influences, I’m baffled. They look like what they are, which is – no offence – scruffy students slumming it. There is nothing on show that screams, or whispers, Mod. Listen – they’re speaking gap year Esperanto: Dr Martens boots, charity shop jackets, indie badges, NHS glasses and studiously just-fell-out-of-bed hair. Damon Albarn tries to do a bit of a Pinkie Brown psych-ward glare but it’s pitiable – a strong breeze would knock him over. And is that shirt unironed? Mod! You mugging me off? It’s four art-school herberts leaning against a car that’s not their own in a world that’s not their own, that refers to precisely nothing outside itself except other half-digested references. Just out of frame is a tacky Essex nightclub called Oscar’s, complete with a big fake blow-up Academy Award statuette. This does seem apt.

Noel Gallagher has a tiny bit more claim to Mod bona fides, although Oasis’s boilerplate music – where the Flintstone rock aesthetic rules supreme, to a point just short of prophylaxis – seems about as far from the original cosmopolitan dream of Mod as it’s possible to get. Weight is untroubled by these lacunae: if it looks like Mod and walks like Mod it goes on the lightbox. (A quick aside on the photos: if nothing else, you would expect this to be a major treat in a book about Mod, but there are notably few images of real Mods among the cross-section of rock groups, fashion shoots, book covers, a snap of Bowie from his least Mod phase and a recent Bradley Wiggins mag cover. Actual Mods in the wild? Nothing. A tabloid snap of Mods scattering Rockers on Margate beach is a distant seagull’s eye view of blurry matchstick men. An after-hours photo that purports to show a Mod couple in a 1960s club also frames a stray can of Hofmeister, which suggests the pic was taken much later.)

Mod’s ‘very British style’ was initially a tasteful synthesis of American flash and European savoir faire. By the time of the first Mod revival in 1979, the once omnivorous sensibility felt moody and shopsoiled – a Mod Airfix kit, complete with decals. All the arrows turned sharply inward. Mrs T had logged 14 months in Downing Street by the time revival-barkers the Chords released what amounted to a manifesto-lite, a 45 called ‘The British Way of Life’, which does sound rather like a kids-are-alright re-voicing of Thatcher’s ‘Where there is doubt, may we bring faith.’ It is this Little Englander, stodge-with-everything revivalism that means Mod is now often seen as hopelessly backward-looking, beached, a sad hobbyhorse. I’m not sure how aware Weight is of this – he certainly underplays the extent to which ‘zombie’ Mods are mocked and reviled in the pop media. ‘Mod revival’ is used as shorthand for a ploddy, meat-and-potatoes rock conservatism: so-called ‘dad rock’, with Paul Weller its peacock-suited John Major. (Even in the mid-1960s, Mod was already partial to raspy, gimme-gimme singers like Steve Marriott, and what was considered their more ‘authentic’ grain of voice.)

Today, we’re again in the middle of a full-blown Mod revival. If you take the trouble to follow a few Mod-related Twitter feeds, you’ll discover a scene in boisterously rude health. (First impression: it’s far more laddish, not at all ambisexual and far less of an aesthete’s playground than the original scene.) Every weekend there’s a clutch of events to choose from – coastal get-togethers galore. This marks, what, a fourth or fifth generation re-revival? There are tribute bands who have tribute bands. There are original bands with no original members in their line-up. Getting a set from pantomime ska band Bad Manners is considered a real coup de théâtre. What this looks like, from the outside, is a postmodern end-of-the-pier show. Beer and scooters. And yet, while it’s easy to sneer at its degraded state, I’m torn. Part of me knows I’d have a pretty good time at some of these gatherings. By my third pale ale I’d be talking Big Youth and brogues with the best of ’em. I grew up with this stuff, it’s in my blood: I hitch-hiked, full of Pro Plus, to the original Wigan Casino; I went to ridiculous lengths to get hold of import reggae and soul 45s. There are photos of me from 1979 in full Rude Boy fig. (I still miss that particular pork pie hat.) Scarily, bizarrely, I’m something like an elder of the tribe now.

But where Mod once gave off a jumpy static of something arcane, unstable, unreadable, it now betrays an air of fussy self-satisfaction: neat alphabetical rows of old 45s on the Immediate label; original pre-loved bowling shoes in polythene; repro vintage guitars and rebranded clothes lines. Sex and drugs and rock and soul, minus the crucial Dionysian spark. Mod has become something to collect, a subcult first edition. On a recent afternoon spent in the stagnant pool of daytime TV, I came across the renowned impressionist Rory Bremner (known for his ‘sharp satire and unforgiving political commentary’) giving himself over to a satirical – sorry, sartorial – makeover, in a Brighton boutique which specialises in everything Mod. The odd thing about this (OK, one of the odd things about this) was that, post-makeover, it was hard to see any real difference. Bremner must have started his day in the soft hands of a TV production company stylist anyway, plus he wears what everyone un-young and half-savvy wears these days – a nice mix of Paul Smith and Margaret Howell, I’d guess. There’s no such thing as ‘subculture’ now, and there’s definitely no real generation gap. Where Townshend and Davies once sang about the alien tea cosy world of mums and dads, by 1990 Shaun Ryder of the Happy Mondays could ruefully start a song: ‘Son, I’m thirty.’

At this year’s Glastonbury festival, young students danced to the seventy-year-old pied piper Mick Jagger, while their parents ‘had it large’ with shouty grime acts. For sure, there were odd pockets of tribal homogeneity, but you’d have been hard-pushed to identify any of them as ‘Mod-inflected’. You could argue we’ve never been less ‘Mod-inflected’. We’re all about the casual tracksuit and the ripped denim shorts, rather than suits and ties; we’re shamelessly confessional rather than broodingly cool; we’re ad hoc tattooed rather than buttoned-up tight. ‘We are all modernists now,’ Weight says. (I don’t think he means we’re all Charlie Parker fans, though it’s a nice thought.) One problem with this is that he’s celebrating the continuity of something that no longer exists. As a result of Mod, he says, ‘it is true to say that more British people came to see themselves as modern than ever before.’ Sure, fine, maybe, even if that ‘ever before’ feels a bit fudgy. As a result of Mod (and the newly hot postwar electric media), a group like the Who could reach millions of people in one lightning-flash TV appearance. A kind of modernity was also what cool 1950s jazz and jittery 1960s rock had in common: they dared their audiences to measure themselves and their world against the music’s stark or playful, soft or apocalyptic new tones. But what exactly was being illuminated here? What were the strange codes passing back and forth between audience and stage? And why was there such disappointment and introspection and withdrawal later on? Doesn’t the more basic point concern not so much this or that movement or scene, as the very idea of ‘seeing ourselves’? Wasn’t this the real modernist key change?

At the end of a numb day spent with Weight’s snap-happy Lego of statistics, I put on Miles Davis’s Kind of Blue in an attempt to really hear it again, to catch the original lure through all the intervening time-fuzz. I say ‘original’, but by the time I came to it Kind of Blue was already 15 years old – it’s harder still to imagine how it signified in 1959. How can something so feathery and frosty and rapt still cause such deep shock? It may be hard to believe, now that it’s become an everywhere gastropub soundtrack, but hearing music like this for the first time could be a dizzying, even upsetting experience. Yes, it contains a sense of hard-won joy – but also sharp overtones of siege and fear, loss and regret. If Kind of Blue was a specifically modern achievement, it’s in part because the players were unafraid of the deafening silence at the edge of their sound. There were darker, more jagged emotions under the elegant façade, something beyond hot trends and cool shades. I instinctively distrust any over-reliance on the word ‘soul’ in music criticism, but it’s the only word that comes to mind here, a code word for all sorts of dreams and difficulties. For anyone back then, 1959 or 1974, raised in a UK household where neither introspection nor exuberance were madly encouraged, where home life was a cramped, stifling affair, and where you didn’t have a readymade language for certain unruly feelings, music like this could really melt the inherited chip of ice in the heart. It still can.

Interviewed after he’d left the Kind of Blue line-up, the pianist Bill Evans said: ‘The simple things, the essences, are the great things, but our way of expressing them can be incredibly complex.’ Evans was a neurasthenic-looking white boy in an all-black band, a man with a bruised, lyrical sensibility in a world that could be blithe, even brutish. You could spend years exploring Evans’s sublime solo work, trying to work out why his playing – which can seem gossamer-light, one register away from rosy banality – is so haunting. Evans looked at times like an algebra professor who’d walked onto the wrong stage. He had the classy Ivy League suit and never a hair out of place, but his private life was a hurtling fugue, a circular to-and-fro of self-cancelling feints and narcotic stratagems. The arrows here all point inward, after the manner of St Sebastian. ‘The simple things you see …’

It may be unrealistic to expect a zippy book like Weight’s to delve into such areas, but the complete absence of any depth or surprise feels wearyingly familiar from recent TV. There, bland retrospectives suck on past lives and leach all the contrary gristle and blood from their hard-won victories. ‘From the boutiques of Brighton to the aisles of Ikea … modernism strutted its stuff.’ Weight’s spayed, odourless jargonese is to real analysis what a TV makeover or a ‘scooters only’ weekender in Margate in 2013 are to the original modernist dare: a perfectly glossy simulation, with all risky elements stowed.

Just as empty shipyards now house ‘themed’ museums – press icon for ‘Virtual Wage Packet Experience’ – so the insane over-ambition of mid-1960s pop and rock has been repackaged as a tidily groovy heritage resource. In the British Music Experience, for example, installed (where else?) in the former Millennium Dome and created ‘to fill a gap in the UK Heritage Sector for rock and pop music’, what did they choose as a logo? Right first time: the ‘classic’, ‘iconic’ RAF/Mod target emblem. Among the artefacts on show is Noel Gallagher’s ‘trademark’ Union Jack guitar. To be sure, rock groups themselves are often complicit in this process – it’s probably hard not to be these days. ‘Perhaps, in that sense, we are all modernists now,’ Weight (sort of) concludes. Really? How do the intense ardour and idealism of all those modernist dreams live on in the freeze-dried clamour of postmodernism? Are we really all modernists now? Sometimes we look more like the bloodless archivists of a real gone time.