A few miles east of London's Southbank Centre, some people who are good at sports are running around in circles. Antony Hegarty's Meltdown, meanwhile – a kind of alternative Olympics for vulnerability and shape-shifting – does not fall short of feats of endurance, technical ability and courage. The achievements here are not exclusively artistic. Opening up for New York alternative cabaret star Joey Arias, the muscular, graceful Chrissy Lux performs a Japanese-themed act in which s/he twists herself into impossible upside-down pretzel shapes while spinning six plates on sticks. Those vanilla leotard types could learn something about grace here.
More so than most previous Meltdowns, Hegarty's line-up is an aesthetic autobiography lived out in the flesh, a process that throws up issues of identity, the sublime, and the push-pull of masquerade and honesty. As Arias puts it, "I see why it's called Meltdown: it's all the influences that make Antony what he is." The singer, Mercury prize winner and "future feminist" has summoned his constituent parts and alchemised them triumphantly before venues full of tearful, roaring fans of varying gender identities and sexual preferences (two distinct spheres, to Hegarty's mind). There aren't medals but there should be.
The old adage about never meeting your heroes falls apart here. There's a point towards the end of Hegarty's sweet, funny and slightly uncomfortable conversation with Boy George on Wednesday where Hegarty illustrates with heartfelt simplicity how his own voice was built. The swooping soulfulness comes not from the American influences, but from south London's most famous transvestite pop polemicist. Hegarty sings a snatch of Culture Club's Do You Really Want to Hurt Me and elides it seamlessly into a bit of his own Cripple and the Starfish. Their talk is terrific, too, illuminating and fond. Hegarty, sincere in the American fashion, is keen to talk about deep stuff: "forcing a place for effeminacy in the culture", environmental catastrophe, and how George's 80s image ironically stole from Rastafarianism and the Hasidic sect which "hate gays' guts".
George – droll, kind and candid – admits there wasn't much intellectual method to his cultural pilfering: he just stole Indian women's trousers off washing lines. "My God hated my guts," says Antony, of his Catholic upbringing. "My God helps me choose curtains!" laughs George, a man for whom a thousand "calmer chameleon" headlines over the years finally ring true.
The saddest part is George's voice, phlegmy and undynamic when compared with its youthful sweetness. But he is still a skilful and affecting presence, singing in remarkably good Italian, accompanied by a dextrous guitarist, John Themis, and a female backing singer, Zee Asha. She's a dead ringer for Antony, and nails the high notes no longer available to George. When Hegarty and George join voices for a highly emotional version of You Are My Sister, the molecules in the air wriggle with the pleasure of a circle closing.
Those high notes are a persistent problem for so many singers no longer in their infancy. Cajoled out of retirement for Meltdown's highlight performance, Elizabeth Fraser, one of the more extraordinary vocalists this country has produced, can still channel 96% of the gaseousness that made her records with Cocteau Twins so extraordinary. But even she has two backing singers to perk up her high end, and an effects unit to play with, making this theoretically triumphant return after 14 years a little frustrating in places.
The glorious "tee-hee-hees" and "ha-ha-has" of Bluebell Knoll come early; Oomingmak is full of ancient shivers, from harpsichord keyboards and Fraser's wordless rapping. Just being in the same room as this petite, grey-haired force of nature in a BacoFoil skirt is a thrill.
Overall, though, her set seems very restrained for a vocalist of such intense transcendence. No one was seriously expecting Cocteau Twins, whose gigs were legendarily deafening. But old memories and new versions joust uncomfortably. Fraser's huge band, featuring husband and drummer Damon Reece, is made up of survivors from Spiritualized and Bristol trip-hop circles; Spiritualized and Julian Cope stalwart Thighpaulsandra is the bald guy playing keyboards. Their atmospherics are too often murky where they ought to be sylvan, and Fraser's angelic backing singers are far too kosher and classically trained, askew with Fraser's free-form style. Genesis man Steve Hackett plays folk-Spanish acoustic guitar against Fraser's unadorned voice, the only time she dares go naked.
I miss Fraser's weep-out-loud moments, Pearly-Dewdrops' Drops and Song to the Siren, because I'm rushing to the Wonderground tent, where Hegarty is soon to join club outfit Hercules and Love Affair for their sinuous collaboration, Blind, the first time they have ever performed it live together. I arrive just as it finishes because their gig is running early and the set list is rearranged.
But even without Hegarty, or their other high-profile guest singer of the night, John Grant, the tail-end of Hercules and Love Affair proves to be an antidote to the high seriousness in the Festival Hall. There is sweat and movement as the New Yorker Andy Butler's dance outfit percolate through restyles of house and disco, a more sexually ambiguous answer to LCD Soundsystem. They are not short of singers – three, one of whom simulates orgasm almost immediately. "You belong to me tonight," pouts Beth Mburu-Bowie. But with repetition, the lyric breaks down into "you belong", a subtle but significant change in meaning that suits the heterogeneous bunch throwing shapes in this hot tent next to the fairground.
Perhaps the most remarkable feat, though, in terms of distance travelled from preconception to execution, comes from Joey Arias. S/he is, on paper, a long-established female-impersonating cabaret artist with affiliations to Cirque du Soleil; "doing" Billie Holiday is her "thing". What transpires onstage, however, is nothing short of alchemical again. The band, for a start, are not just cabaret-good; they are jazz-calibre good, with a young, muss-haired female drummer, Allison Miller, who defies physics and bends time.
Arias, meanwhile, looks like Rossy de Palma. But hiccupping, slurring, coughing up hairballs, chopping up her syllables and singing away from the microphone, s/he reminds you of how Amy Winehouse might have performed, 40 years hence. S/he is intense, and funny too, with little jazzy Betty Boop squeaks coming when you least expect them. Good Morning Heartache is mangled and mesmerising; Strange Fruit is delivered with sibilants and plosives laden with disgust. A knuckle-dragging philistine might believe we are watching drag karaoke, but there is nothing whatsoever ersatz about how completely Arias embodies the spirit of Holiday, damaged and righteous, one struggle informing another struggle.
When Hegarty performed at Patti Smith's Meltdown seven years ago, he rushed up to the organisers after Smith did Horses in its entirety, stating that if they were in the market for reboots of underground classics, he had one: Marc and the Mambas' Torment and Toreros. Seven years on, it's the kernel from which the entire Meltdown line-up has bloomed.
The Mambas were an offshoot of Soft Cell and their second, double album remains a difficult listen. Overwrought, clanging and disjointed, the suite of songs takes drama, death, heartbreak and humiliation as a starting point, and it only gets darker from there. But there is no faulting the dedication with which Marc Almond and his enormous band – eight-strong choir, string section, all sorts of percussion – throw themselves into it. At one point, Almond waves a giant black bull's head around, then tries it on for size, an almost pagan moment of defiant nihilism. You suspect every single person who bought and loved the album is in the room, such is the din coming off the crowd.
But the killer blow comes near the end. Listening to Almond's cover of Caroline Says led the young Hegarty to listen to the Velvet Underground and Lou Reed. Then, of course, Reed vociferously championed the strange, tender unknown singer a decade ago. Another circle closes when Almond sings Caroline Says for Antony, with Hegarty, obviously in raptures, joining in.
