Live: Flapping for Feeling. Bat For Lashes, The Forum.

What's in a name? Well, everything and nothing all at once, really. And Natasha Khan's long since established pen name, Bat For Lashes, is one I've always found myself helplessly fascinated, if never fully convinced by. The evolution of Khan from lowly South Coast odds, sods and trinkets boutique proprietor to kooky serial Mercury Prize nominee, via half-baked alter egos and smashing hit singles has set her on an abnormal trajectory toward the apices of pop, although elements of the eccentric remain intrinsic to her every manoeuvre. She's remained true to her schooling in the spectral enlightening of Kate Bush & co. undoubtedly. It's just that with all the imagery of faux-mystique, and the nonsensical moniker the forcibly ethereal aesthetic lacked persuasion. As such her latest and third full-length, The Haunted Man, represented a neat cross-pollination of the more glittery bits of her disco-flecked past and a more exposed artistic nudity since assumed – encapsulated quite explicitly by its much talked about sleeve artwork – as she now sets about embarking upon a perhaps somewhat unsure future. Khan turned 33 just last week, and there are signs of an ever advancing maturity within – the sweeping grandeur of Marilyn, or the subtly immortal orchestrations of Winter Fields. Did she just outgrow the face paints as most thankfully do at some stage in the wake of the innately disheartening phenomenon that is Freshers' Week? I'd like to think so. Although for once both the face paints and Khan's chiropteran nom de plume carry a resurgent significance, what with it being Hallowe'en week. And aside from a frightfully apathetic audience, there are moments of the marrow-quaking tonight.

Having been inspired by the liturgical compulsions sport rouses within the average obsessive, this all-pervasive ennui is somewhat problematic both for we and, I'd full well imagine, she too. There's the odd flailing forearm here and there to which Khan will cling as though withered driftwood out on the sold out and supposedly highly cultured seas of choppy ambivalence, but otherwise she's more or less the only one shimmying. There may be myriad excuses: overdue impetus placed upon newer material; it's Monday; it's lashing down outside. But where the live music experience often carries a quite unifying effect, tonight it disconnects to a lamentably discernible extent. Which is a tremendous shame, and a shameful display on our behalf. There's more kinetic energy in the swing of a pagan pendant dangling from her neck than there is in this entire crowd combined, just to clarify.

And the realm which Khan now inhabits has to be questioned within this context as we trawl all reason for rationale. For she finds herself stalking the rather barren territories between the left field and the mainstream. She's gambolled the length and breadth of the bucolic and creatively liberated former, yet sipped from the murky waters of the latter. She is free artistically, and yet is unmistakably infected by commercialism on a major scale; emancipated from the leaden pressures of pop, and yet was first snared by one of its major players five years ago. If you're of a glass-half-full demeanour you might say she's an upstanding lady of contrast. If it's looking a little on the empty side then you might say she is a construct of contradiction. Tonight being her finest performance digested by my eyes and delighted in by my ears, I'll err on the side of the former opinion although how many others here congregated share such a view remains unclear. It's thoroughly; exasperatingly opaque as to how many hundreds are dedicating all that much attention at all.

But Natasha flutters on irregardless, if never oblivious.

The show begins, as does The Haunted Man, with Lilies. It's an apposite place to start, as its lyrics of hands clenched tightly between twiggy thighs above blackened knees serve as a continuation of this more sensual method Khan has scrupulously cultivated in the interim period between Two Suns and now. Swathed in slivers of backless black and white, she veritably glides amid styrofoam scenery that, coincidentally, looks like dislodged hunks of moon. More pertinently however, this clinging to a whisper of that mysticism past suggests Khan still finds herself in transitional backwoods; of course contemplative, although as yet unsure as to who she is, or wants to be, or even desires to purvey.

Make no mistake – there's still a purposefully, markedly projected image at play here. I've no qualm with it, and indeed I think some of the finest performances of modern times have been just that – performances recited by personas. And Khan has become a quite transfixing live performer in her own right. Perhaps that goes some way to elucidating our collectively static reaction – we've been stunned into submission as one. As I begin to wonder, and doubt, and reconstruct the question however, she hits a vertiginously high note, chiming: "Thank God I'm alive." Maybe that pendant wasn't belonging to pagan stylisation after all. The lyric stands out irregardless of belief, and stands as a truly startling avowal. Has she finally found the real her, whatever that may transpire to be?

It's another question, and I've already an arsenal to ask of her. What is unquestionable is that there are certainly far more further Qs formed than As responded to tonight. To what degree are the cellos and bowed guitars on an immaculate Glass essential to the overall sound, as opposed to a byproduct of a more avant-garde mode slipping into the contemporary? Its rhythms are guttural; gnarly, almost as eleven filaments ensnared in translucence illumine her every move. Thrashing out grooves from a drum pad, she couldn't be more focal and together we comply in scrutinising her as may a zoologist unleashed upon the wilds for the very first time. She for once cuts an imperious and openly observable figure, those banshee wails of its closing moments hollered with an haute supremacy; as though the pained cries of a siren stranded out in said boundless wilds.

She keeps with Two Suns, embarking upon Travelling Woman. It's eclipsed by the unfiltered radiance of her poppier compositions tonight, and raises doubts as to whether she now finds herself beyond balladry. It somehow feels disingenuous. PJ Harvey's been blowing this game out the water, dry ice, and everything else since White Chalk, and before an astonishingly hesitant multitude she's better off with rather more spring in her fleet-footed step. She here visibly; forcibly tries to cajole something; anything from the stalls a metre or so below. As a performer, she feeds off her doting, and with that nicely diversified contingent but tonight she's feeding off scraps as may the bats of Parliament Hill come Sunday nightfall following on from a weekend's revelry. "I kissed the road, I kissed the road/ And I came home to the love you gave" she'll later brood to the clipped rhythms of Horses Of The Sun, and if London may only be 50-odd miles off a Brighton homecoming then emotionally, this is lightyears off any form of reciprocal affection.

Impassivity again predominates, prior to a minimal, though still majestic All Your Gold. With a shuffle of exposed shoulder, she meekly proposes: "Some of you may know this one." It's masterfully refined, scintillating pop at its most knowable, and yet it's treated as though an unknown; "a heart from the past" eradicated from memory long ago. Music moves quickly these days, but really?

It takes Laura – somewhat inevitably – to ruffle a few feathers. An inherently lonely song and one intended as such, it does indeed unite as we stand in stupor whilst Khan delivers its strained refrain of "you're more than a superstar" from a figurative plinth loftier than the multistory heels of its central protagonist. It's theatrical in impact, and although there's not a single sodden eye in the house every one remains spellbound throughout. It ends, and every mouth roars. As Siren Song kicks up, someone faints – overcome by its enduring potency.

But this is Khan again in balladeering mood. And, again, her onstage persona may be perceived as not so much a fixed personality, but more as a splintered duality of character. What's A Girl To Do maintains the sense of the sensual, despite being born of a time when feathery headdresses were of paramount importance as Khan is caged by the framing of the stage itself. And, as lights flicker about her lonesome figure, they begin to cast imposing shadows of she herself – shadows that loom over and gaze down upon her, accentuating this refracted view of fragmented character.

Elsewhere, she demonstrates a childlike glee toward new ones and new routines, as she shimmies with great beguilement to the soft tribalisms of Oh Yeah. She gestures perfunctory waves to the back of the room, whilst the front chants its mantric calls of "oh yeah". She looks like a pop star, and we react accordingly – mouthing just two words over, and over, and over ad infinitum. But is it the sort of pop star she longs to be? Or could even bear becoming? It all becomes rather ambiguous.

Marilyn – drenched in thalassic guitars and clouded by a backdrop of a grey sky, thereby imbuing the single with the feel of your typically British festival – goes out to her present mum. The dedication is greeted with a faintly impassioned aah, and although enhanced live it's ultimately unremarkable when it ought to have been utterly monumental. Horse & I too falls a little short, so limp is the reaction to yet another single. But that's the thing – pop stars have singles. Their singles sell, and their lyrics etch themselves into short-term memory. With regard to such stuff, Natasha has Daniel. It's tonight overdone and overly bombastic, but it's still quite brilliant as off-kilter, chart-plaguing things go. But otherwise, there's little else of the sort.

"Are you ready to clap?" Certainly! Sort of. Irrespective, and with that irrespective of the skyscraping pedestal down from which Laura resounds, Prescilla remains her pièce de résistance; her closest of figurative friends. Quicksilver guitars slither through strokes of chorded zither and primitive rhythms, before its lukewarm charms are chilled a touch to a Scandinavian sterility. We're now deep within a bass-hefty, grubby Rest Your Head. The ante upped, the atmosphere builds. She clatters right on into A Wall, and straight through into a joyous Pearl's Dream beyond. It's a heady climax; a dumbfounding, show-stopping denouement and yet Khan appears overcome with reticence. These are her crowning pieces; her kings and queens on the chessboard of popular culture – the culture to which I was once sure she belonged.

Maybe this world of immoderately branded venues, and the compulsive compartmentalisation of absolutely everything, and questions lacking answers is but a game. A sadist's plaything within which Khan's wings were ever meant to beat. Maybe the greatest mysticism of all is the mystique of ambiguity. But in opening up to us, it would perhaps appear we've no room left in our hearts for The Haunted Man. Which, if true, would be an egregious discredit to a genuinely invigorating artist.