So what to make of this noise now, with British pop restored/reduced to chirpiness, choppiness or chippiness, everyone running around like idiots? I suppose it should sound dated. It doesn't: My Bloody Valentine's breathy roar, reissued into a new century, stands outside of time, is stronger than time. Their flaws are perhaps more obvious with hindsight, not least because those flaws - "excessive solipsism, fussiness, overindulgence" - led directly to their disintegration, but the helpless immediacy of this sound could never be anything but contemporary, and the reach of these records makes bands yet to form sound hopelessly out-of-date.

Isn't Anything was startling even in the climate of 1988, the last time rock felt the urge to experiment rather than indulge itself, perpetually, in parody and celebration. While its roots show through in songwriting and performance, the sound of this record owes nothing to the past, in any sense - livid, lurid and lucid, it's the shattering racket of the moment, an audio snapshot of the overwhelmed senses, a noise like nothing you've ever heard, but everything you've ever felt. Rather than rock, My Bloody Valentine played the tones and textures of raw experience: the weight of the air before a thunderstorm, the shifting hum of psychosis, the quickening blood... it's all there in the warped babel of wildfire guitar. ’Soft As Snow (But Warm Inside)’ and the juddering ’Cupid Come’ are stop-start simulacra of sloppy, stoned sex (the latter lurching to a fiery aural orgasm), the smeared, muggy ’Lose My Breath’ finds transcendent bliss in oxygen deprivation, ’Several Girls Galore’ breathes mind-bending life into themes of disassociation and depersonalisation. Throughout, they sound like newborns reeling in the light, every sensation a delirious, unmanageable rush.

Where Loveless is blanched, Isn't Anything is vivid, even in the cannaboid fog of ’Sueisfine’; as Loveless lapses into the simply soporific, Isn't Anything keeps its punch, even as the smacked-out ’All I Need’ slips in and out of consciousness. That's partly down to Colm O'Ciosoig's restless drumming, sharp slaps to the face when the songs start to nod out. On the later album he's submerged, sampled, or absent altogether (having missed much of the recording through illness), and those desiccated rhythms contribute to a certain sterility, a sense of being shrinkwrapped. At its best, Loveless is untouchable - at worst, it's like having lost the sense of touch.

Everything works beautifully on what's still their most sublime piece, the eternally astonishing ’To Here Knows When’, that swishing percussive loop an essential hang-on in the musical equivalent of zero gravity. But when they try the same trick on the pretty-pretty ’Blown A Wish’, all hushed and glowing like it's drowning in seratonin, what I hear is stillness, and rank good taste (fitting that the song itself recalls the wretchedly nice late-period Cocteau Twins). ’I Only Said’ plays gleeful games with tonality before exploding into the sound of a drugged summer, but then the marvellously windblown sound of ’Come In Alone’ can't dispel a certain fugginess. For all its moments of raging glory (and there are more here than in most musicians' drugged-up dreams), Loveless as a whole can be somewhat suffocating.

Constant glare tires the ear - ironically for a record that has no sense of time, this works best in short bursts. For ten or fifteen minutes, that incorporeal awe feels like riding Voyager 1 through the Jovian bow shock; half an hour passes, and you're craving something fresh and green. What you get instead, as the album winds up, is ’Soon’, the second-best thing here and a genuinely radical record in precisely the way that much of Loveless isn't: fading in over a twittering dawn chorus of sampled feedback, its first lurch is like a detonation, and as ’Soon’ pitch-shifts your life, you realise that however stupendous their achievements, My Bloody Valentine were capable of more. Though it's one of the few rock LPs that wouldn't sound better if it had been recorded in four days, much of Loveless is slightly overcooked, and the smooth pressure of ’Soon’ is a glimpse of a future that never came, now drifting further and further out of reach.

(For this re-release, Loveless comes as a 2-CD set, comprising a straightforward remastering job and a new version, “remastered from analogue tapes” by Kevin Shields. The new version sounds richer, slightly warmer - but the differences are so subtle, that might just be the air currents in my room - and I have no idea what justifies the double disc. Nothing better illustrates the mix of indolence and perfectionism that was My Bloody Valentine's downfall: aversion to new activity, compounded by an irresistible compulsion to tinker.)

But musicians are lazy people, and seventeen years of silence is vastly preferable to what the Valentines' successors did with this monstrous motherlode. Much was made of MBV's abandonment of “the band”, rock's kineticism displaced by many-angled blasts of pure sensation - but the point was to liberate the music from its own history and the demands of the form, open up vistas of mouth-watering possibility. But in the end, the most influential thing about this music was how effortless it all sounded - an illusion that killed. A thousand clots turned the guitars up to 13 and stopped listening to each other... and so, a new orthodoxy: out went words, instrumental interplay, the outside world. In came self-absorbed, soft-focus slop, a mussed and woozy waste. The rot had set in with The Jesus & Mary Chain's sullen immobility, but it was MBV who poisoned British guitar rock for more than half a decade (and left a legacy of laziness from which it's never really recovered). What can you do? Offer some folk an apple and they'll choke a pig with it. These bright, intrepid records sired a generation of sludge.

Yet here, still, My Bloody Valentine sound wide open to the universe, the opposite of blank, the opposite of bland, and their historical significance can go hang, because everything that's ever happened, or ever will, is happening right here and right now in the best of this extraordinary music.