All live photographs courtesy of Unsound, and burning piano photograph by Helena Majewska

Don't worry. This won't be one of those reviews where the writer refers to the theme of the festival every twenty words. The idea of curating a concept-based event such as Unsound is considered recherché in some quarters, perhaps counter revolutionary in others. Personally, I'm all for it as these are impositions that mother invention. It's my feeling that the theme, if not too nebulous, can simultaneously make organisers, artists and attendees think more critically about an event while generating more flutter and wow.

dəəp authentic, this year's theme, has post-, or more realistically, ongoing pandemic connotations, touching on how COVID-19 has pushed us further into the virtual realm and how tentative steps towards IRL cultural events now necessarily feel different. The idea has associations (via Pauline Oliveros) with deep listening, while also pointing at the sometimes extreme and paranoid edges of life: deep state, deep fake, deep web; while authenticity is an ever hot subject, now brushing up brusquely against cultural appropriation, crypto-art, microdosing and so on.

But Unsound is at its best when artists think laterally about such themes. It acts as the 'head' in a free jazz excursion: the comparatively tuneful opening bars that continue to echo round the ears of the listener while the musicians move purposefully away, leaving the rest of us to wonder how they'll ever make their way back again.

At the Krzysztofory Palace, artistic director Mat Schultz zips about resolving last minute problems, a period of catastrophe management and disaster surfing of unspecified size, nature and duration now clearly just behind the team. When told that everything as observed at the point of use appears to be running as smooth as an engine freshly lubricated with Castrol GTX, he says: "That's a relief because I was watching the documentary on the Fyre Festival and everything the guy was saying sounded exactly like something I'm usually saying…" An exaggeration probably, but the bell curve of festival organisation in 2021 is probably terrifyingly steep and very, very tightly packed, the things separating a successful event from an unsuccessful one, frighteningly close together. Who would want to scale such an imposing peak?

On first encounter then, this year's theme suggests nothing more than a deep and authentic sigh of relief that something as dedicated to new music, digital art, emerging technology and contemporary cultural thought is still operational in a post-pandemic landscape (if reduced in size somewhat).

After collecting a wristband I have an NCT attached to my right thumbnail by a bejewelled academic called Wet Me Wild. When the tiny microchip-sized nail adornment is attached and scanned by a smartphone it fires up a festival programme. It's an office hours piece of durational performance by a hydro-feminist whose practice usually relates to climate emergency, so the depth and authenticity of the experience is directly proportional to engagement with the idea. (Annoyingly, the NCT is ripped off during a rambunctious swell on the dancefloor during aya's set later that evening, way before I have time to work out how to use it.)

Just this week, London-born, Chinese-Malaysian musician and author Flora Yin-Wong told Aug Stone on this site: "Ever since I was young I've felt there was another layer of things to the world, and I guess we're all just trying to describe what that is." She sits on stage backlit by fierce red gels and spots. Struck, plucked, strummed, rung, hammered and beaten, metallic and wooden tones are in balance with reverberant digital murk as she incants slowly about precognition, parallel lives, time and predestination, with the eerie set ending in suitably Ape Of Naples-esque organ lines.

Bendik Giske by Helena Majewska

We are beckoned further down into an aqueous sonic environment by Bendik Giske, a saxophonist from Norway who is having a live send processed subtly by Bridgit Ferrill. At first the clatter of keys, drawn up and out of the recording into a rhythm section, contrasted with an initially muscular display of circular breathing causes a knee jerk comparison with Colin Stetson, but this is dropped almost immediately as being inaccurate. Actually the deep wells of echo and ever changing spatiality of reverb, as arpeggios, riffs and motifs are cycled through different takes and permutations, are much closer to the aqueous vistas mapped out by Arthur Russell. I imagine the joy that could be felt during this gig were it possible to recline in a hammock for the duration, but it is now easier to imagine the end of the world than it is to imagine some hammocks for 50-year-old reviewers with lower back pain to lie in during experimental music gigs.

Later at Hotel Forum, lumbar discomfort is forgotten as local synthesist Charlie turns in a brilliant set. At first the obvious comparison to reach for is Miss Nicky Six, as the vibe is one of thumping, analogue, Belgian new beat. But x is never 'just' y, and there's more to this than mere battle re-creationism. I like watching DJs turned musicians, sussing out transferable skills. Tonight's set on Sequential Prophet 6, Juno-1 and Cirklon etc isn't some act of hardware fetishism, because the songs mix from one into the other, key changes are observed carefully, tempos are either maintained or changed ostentatiously, comb filters are swept, band pass and low pass filtration applied, sweeping phase deployed, and songs are sequenced with maximum dynamic impact in mind. This is gig as DJ set with all the dynamic peaks and valleys which that suggests.

A lot has changed for Aya Sinclair since her raucous, exhilarating and hilariously banging set in the same building two years ago. She has become fully uncoupled from her former name LOFT, and with it, the last (hotly debated) link to deconstructed club music. Not that I'm an expert but I don't think it's all that bad a descriptor for what she used to do – despite the limiting scene baggage that comes with the name. It was simply a necessary phase she went through. In Jungian analytical terms the deconstruction (rather than outright destruction) of the ego of ideas, has been followed by individuation, or the construction of a new self or ego out of the myriad constituent parts. Is this simply fancy hot air? Possibly, but so thorough has the rebuilding process been that it's now next to impossible to say with any great certainty what clear influences have gone into the set (which is a run through of her ace Hyperdub debut im hole)... hip hop, grime, bass music, acid house, footwork, poetry, noise, techno… you can say 'possibly' to all of these things, but nothing is cited expressly, nothing is worn on the sleeve, nothing is clearly copied, reference, reproduced or sampled. This isn't simply recombinant. Is it… something new? Now there's an idea worth deconstructing.

Robert Aiki Aubrey Lowe by Zuza Sosnowska

It's a total guess but I would assume that notable international arts festivals probably stand or fall in terms of funding by the headline-grabbing shows they can either commission or attract. I don't want to come across as too much of a contrarian but these big event shows can sometimes be the things which leave me cold. I find that if I want to see a DJ at their best then I go and watch them on the decks in a packed club; I'm not sure that I need to see them recreating Peter And The Wolf with a 32-person turntable orchestra and acrobats. On the other hand, sometimes these big stage commissions can really produce the goods. Unsound has a very good track record in either hosting or commissioning, and then pulling off, set piece shows such as Jlin and Company Wayne McGregor's European debut of Autobiography, or The Necks playing with the Sinfonietta Cracovia, and Ilan Volkov performing in the Wieliczka Salt Mine. Unsound also has form for presenting excellent debut soundtrack works. In 2019, it was Hildur Guðnadóttir presenting Chernobyl with Chris Watson and Sam Slater, and this year it is Robert Aiki Aubrey Lowe's Candyman. An initial problem for me is simply that Lowe is probably my favourite contemporary synthesiser player and I'd always go and watch him play solo, experimenting with a patch, at the drop of a hat, so I'm ambivalent initially about watching him play film score music in a quasi-orchestral setting.

Much has been written about the importance of the Candyman film, and the Nia DaCosta/Jordan Peele remake, which I won't repeat here, but Unsound is giving us the chance to experience Lowe's original score live for the first time, removed from the context of the film. The set-up is relatively complex. Lowe and Matthew Morandi (WETWARE & Jahiliyya Fields) sit stage right equipped with modular synths, electronic recording equipment and keyboards, while Randall Dunn (of under-regarded fourth world chaos magicians Master Musicians Of Bukkake) is mixing at the front of house. Near them stand singers from the AUDIVI Cracow Vocal Quartet. On the other side of the stage is Iga Ćwiek on contrabass, cellist Resina, percussionist Hubert Zemler and Kraków's Spółdzielnia Muzyczna Contemporary Ensemble.

Lowe initially made recordings on location during filming and incorporated these into his score. The area was his former neighbourhood: Cabrini-Green, a city block-wide former housing project in Near North Side Chicago which was raised in 2011, but none of these subtleties are lost in the live setting. Tonight the electronic, the recorded and the acoustic are integrated in a really pleasing, impactful manner. The ensemble and singers are conducted by musical director Brent Arnold in a traditional manner but with sends going to Lowe and Dunn, who manipulate, process, dub and mix the sound in real time. For example, Zemler has a tattoo of rim shots, fired out into a deep 5.1 field and they clack about, ping-ponging left to right at the back of the hall. A glockenspiel refrain gets fed through Lowe's modular and the notes begin to break apart, becoming an acidic scree of metallic noise.

The overall vibe leans near cool touchstones of score writing: the minimalism of Philip Glass, the area where György Ligeti's choral micropolyphony crashes into electronic music, and that sweet spot somewhere between the avant-garde and the orchestral that Morricone hit with soundtracks such as L'uccello dalle piume di cristallo, but, as with the film itself, nothing is quite what it seems and cultural history is being viewed via an array of cracked mirrors. And if it feels like the White European canon is being interrupted and challenged by innovations in 20th Century Black music, then I'm guessing that's no coincidence. The music hits several peaks when it achieves an intense electroacoustic orchestral analogue of industrial techno and simultaneously points at my only real problem with this set-up: I'd like to see more of it. The idea of Lowe getting to use a set-up like this to create original work that doesn't have to hit the same beats as a commercial film, is one that should be seriously considered, by the people whose job it is to consider things such as this.
John Doran

Angel Bat Dawid by Jovan Mrowinski

Embedded throughout the weekend are the sounds evocative of the pandemic – there are frequent sirens, alarms, a hellish foghorn herald – that operate as calls to action, but are also manifestations of the panic of the pandemic. They appear as rising panic in Speaker Music, in Quincy Jones' 'Ironside' siren in the dirty rap (in robot wings) at LSDOXO; in The Bug's opening salvo. They are a call to action in more than one way, and I hear them also as a reclamation of place for artists and their audiences; a territorial assertion of the presence of live music.

Later in the weekend, the sirens give way to reflection, which begins at the church of the oracle Angel Bat Dawid, who holds a healing service in front of a slideshow that includes an animated GIF of the 26,000-year-old Venus of Dolni Vestonice strutting on the spot. Spoken words, reeds and piano form a sort of cosmic jazz variety show that ends in a collective chant and a promise that we will all take more naps.

On Friday night, DJ Scotch Egg plays as DJ Scotch Rolex with MC Yallah. Dressed all in white under blood red lights, she lays down an apocalyptic flow; doubled down on when Duma's Lord Spikeheart strides in roaring destruction in his death metal growl. Scotch Rolex's pared back rhythms are raw scorched earth – all rattle and rumble. It's really fucking evil, the most minimal I've ever heard Scotch Egg, a cataclysmic Friday night shake down.

It's unclear if the cavernous bass is transportive because of the hollow, responsive space of the HypePark warehousing, of if the pandemic has neutered how much I'm used to hearing sound with a scale and power like this: the warehouse doors rattle on their hinges and the subs seem to be vibrating not just my chest cavity but the very follicles on my scalp and my eyes in my skull.

Diaki by Helena Majewska

Elsewhere, DeForrest Brown Jr.'s Speaker Music is teeming with brittle irregular percussions that deform into rising cacophonies of sirens; the whistle pips of Menzi's sprung gqom productions are like fishing wire suspending impossible bass rumbling like jet engines in mid-air; percussionist Qba Janicki renders in precise acoustic patterns the drum machines that populate the club space, and Drain Gang co-founder ecco2k's fanbase get riled up like teenagers – they know all the words and are screaming requests, giving his pre-midnight show the overwhelming sense that it is a big pop act on the cusp of breaking through.

Hearing amapiano for the first time in a club, courtesy of UK DJ Shannen SP (who curated the 2021 NTS-released Amapiano Now compilation) is a baptism of understanding. While this South African house genre has had both NTS specials and spots on DJ Target's BBC 1Xtra evening radio show, it takes hearing the silk and swish of its productions, the glittering tops and the snap and ping of its vocals on a full soundsystem, to fully comprehend its shape and appeal.

Nyege Nyege's Diaki has a MIDI keyboard added to his DJ set-up from which come sound effects and hammered keys – blood curdling screams and babies giggling, among other assorted sounds. It is a sort of Shepherd tone in percussive BPMs, in that it appears to increase forever in speed and intensity and torque, as the loops get shorter and shorter until it affects a sort of sonic ego death (when I start hallucinating repetitions of "let's bail" in its vocal micro-loops I know it's time to leave).

Sam Rolfes and Danny Harle's Harlecore show is like having your face smashed in by an anime; its colossal throbbing hoover stabs and hamster-trance vocal samples are turgid and bombastic, and not just in terms of the sound but also in terms of the superfans in the crowd. There is the mood of a full-on stadium concert: multi-coloured laser nets scan the audience while Rolfes' big screen AR visuals place Harle (in Jesus pose) into a sort of infinite cyber-stadium, not wholly unlike a CHI rendering of Norman Cook's wobbling inflatable booth at the 2012 Olympics. However, it is the texture and power of the productions that make the venue feel much bigger than it is: they are totally swole, with EDM singalong moments for Harle's edits, including an incendiary unreleased version of 'Visions' by Charli XCX.

Sam Rolfe vs Harlecore by Helena Majewska

It is like hitting maximum spangle but for 45 minutes; the totally wired moment of the absolute pinnacle of an ecstasy peak, but maintained for a whole set. It's completely overwhelming if you're accustomed to hearing a track for minutes at a time, although I'm loath to read the snapshot structure of sets like Harle's as a mirror of the bitesize sharing culture of social media.

The Bug opens with a tuned and treated introductory suite of manipulated foghorn recordings, the already huge metallic hollers tweaked to become truly monstrous voices. Thanks to 20 minutes of dry ice before the set opens, the crowd is sunk in a fog that suspends space and time, the sensory effects of which only amplify the sonics. Halfway through, a pit forms in the fog; a swirling mass of sweating, screaming bodies. I'd expected to be blasted into outer space by the low-end, having seen a shot on Instagram of an imposing row of speakers at soundcheck earlier in the day, but the clarity holds the balance, and it's the energy coming off front of stage – from MCs Saint Hilaire and Flowdan, who bounce off one another like thunder and lightning – that cleanses the anxiety grime of last year's lockdowns from the synapses.

Afterwards, RP Boo and SHERELLE really only have to keep the coals hot, but they go so much further; a seamless b2b bubbling with a wonderful giddy joy through footwork classics and fast edits (including a Genesis footwork mix RP Boo has been dropping recently).

In a Q&A, the composer of the weekend's finale, Annea Lockwood, articulately described her work as being about the transfer of energy. Her piano transplants are a series of works that she began in the late '60s, the most famous of which is Piano Burning, which instructs to set an upright piano (one beyond repair) on fire, by placing a twist of lit paper in the body by the pedals. It was never a destructive piece, but one that was about a liberation of sound, among many other things. After the alarms that sounded throughout Friday and Saturday, the relative quiet of crackling flame that comes from a piano engulfed in flames becomes a deeply poignant and contrasting moment, and a social one too. A fire is that around which humans have gathered for millions of years, whether or not it's part of an avant-garde installation, and so people remain well after the spectacle of the piano collapsing, and chat around the bonfire. There is much to be read into the flames, but it is, more than anything, a reminder that festivals like Unsound are about coming together.
Jennifer Lucy Allan