Cigarette-sized, they allow the audience to flicker prettily during the Plastic Ono Band set that opens the festival, turning the fourth wall into an expanse of fireflies, and drawing the crowd into Ono's realm, where music isn't separate from visual art. They come in quite handy taking notes in the dark, too.
Although Renaissance curators have passed this way before (David Bowie chiefly, in 2002), few Meltdowners will have brought with them the genuine, multi-platform, visual-auditory-conceptual reach of Ono. For someone so physically diminutive – it's still a shock to be reminded exactly how petite Ono is when she scampers on to the vast stage, trademark shades perched on her nose – Ono's scope remains impressive. Her first trade, as conceptual artist, is represented on screens and in various happenings throughout the fortnight. The Plastic Ono Band's event-opening set is prefaced by No 4, a 1966 film featuring bare bums in all their hairy, dimpled glory. If Ono was made famous by writing YES on a ceiling in London's Indica Gallery in 1966, her very name is refusenik: ONO. Tensile strands of feminist and environmentalist activism run through her programme, not least the timely focus on Pussy Riot, two of whom still languish in Russian detention camps.
You really don't get the feeling that the South Bank's arts mavens handed the fearsome Ono a list of names (some bankers, some trendy must-haves). The curation here feels quite real. These days, the Plastic Ono Band is made up of Sean Lennon, Cornelius (the Japanese Beck, they used to call him), plus Yuka Honda of 90s quirk-rockers Cibo Matto, who have their own gig too.
Former partners in Sonic Youth Kim Gordon and Thurston Moore are both present – albeit on different nights, with different outfits; Ono has collaborated previously with both of them in 2012, as YOKOKIMTHURSTON, the former couple's first ensemble artistic output since the break-up of their marriage.
Moore's set on Wednesday is slightly misleading. As he is billed under his own name, people might be expecting tracks from Moore's fairly conventional solo work, in which he plays guitar (with his hands, not with random objects) and sings words with his voice.
Instead, this set ropes in London's top line of improv jazz musicians for a roiling set in which chaos unfolds within structure. It's thrilling stuff – especially the hummingbird hands of drummer Steve Noble, and the way double bassist John Edwards hits his strings with the butt of his bow – but probably less so if you were expecting the acoustic songs of Moore's 2011 solo album, Demolished Thoughts. Some wag has posted footage on to YouTube overdubbed with a perky tune.
Gordon's Body/Head project, meanwhile, is anchored a little more recognisably in Sonic Youth's avant-rock. One track features a little lyrical lift from 1969 ("all across the USA," breathes Gordon) in homage to the Stooges, concurrently gigging in the Festival Hall. If it is hard to believe that Meltdown's powerhouse curator is 80, it is equally astonishing that this tall woman coaxing drifting atmospherics out of her guitar while wearing leather shorts and silver boots is 60. Tonight, Gordon and collaborator Bill Nace are joined by feted avant-drummer Ikue More, who anchors the two drifting, effects-laden guitars with a kit and some subtle processing.
Ono has virtually adopted Peaches, the Canadian singer infamous for her gynaecologically forthright songs and outrageous stage-wear. (She actually should be famous for songs such as Talk to Me, a terrific electro-soul cut stymied by the pop market's unfriendliness to girls who don't look like Taylor Swift, but that's by the by.)
I miss it, but Peaches reprises Ono's notorious Cut Piece (in which members of the public snip off the artist's clothes) at the weekend. During the Plastic Ono Band set, Ono deputes Peaches to yell Yes I'm a Witch, the infamous 1974 song in which the woman blamed for breaking up the Beatles finally hit back against the tides of misogyny and racism that lapped at the Dakota Building. It's defiant, mischievous and funny, with Peaches towering over Ono in sculpted, studded heel-less art-boots.
Midweek, Peaches stages her very own two-act musical, in which her habitual lubriciousness gives way to a teenage fixation with a cheesy musical about Christ. John Lennon got into some bother for claiming the Beatles were bigger than Jesus; in Peaches Christ Superstar, this former nice Jewish girl from Toronto enacts the Andrew Lloyd Webber musical solo, playing all the parts, accompanied by guest pianist Mathias Halvorsencorrect (sitting in for Gonzales) who plonks an iPad on the piano instead of a score.
Dressed in a white leotard with what looks like an albino German sausage for a neckline, the ball-busting Peaches has never seemed so vulnerable. In the second act, kitted out like a rapper with a penchant for tinfoil, she imbues her borrowed material with so much affection that you almost – almost – want to re-examine the output of Lloyd Webber in the light of her gutsy interpretation. But not quite.
Actual sonic youth is, perhaps, just a little under-represented this fortnight. Refreshingly, Savages – all in their 20s – supply both vigour and rigour. They are a foursome who have not yet relaxed into their metier. Indeed, their defining quality is that they never relax.
Live, the tracks from their recent debut, Silence Yourself, are wound even more tightly; songs such as I Am Here are like waves seemingly designed never to break. And while the focus lingers understandably on singer Jehnny Beth, with her post-punk howl and frantic gesticulations, the remaining Savages are all enthralling, especially drummer Fay Milton, whose rolling physicality is a joy to behold. This is, in part, a festival about low-sugar, high-spice female performers, and Savages fit the bill.
There is a blare of guitar and suddenly the Stooges are onstage playing Raw Power and people are spilling out of their seats. Soon after, they are enjoying a sanctioned mid-set stage invasion – led astray by Iggy Pop, the boy from Michigan whose moves made him the nihilist's answer to Mick Jagger. Quite where this band links into Ono's vast network of fellow travellers is unclear, but there are levels of confrontational performance here that sit well with the curator's own.
This latest incarnation features James Williamson, the erstwhile Stooge who had spent 30-odd years behind a desk, then picked up where he left off, grinding out seemingly thuggish riffs rich with musicality. Tonight, the Stooges swing as well as swagger. It is a lot of fun. Of course, that's not a quality in such short supply elsewhere during Meltdown. Even the fig trees in the rooftop garden bar have little signs saying that the plants receive regular doses of a Yoko Ono composition: Bird Song (1997).