Fira de Barcelona, Barcelona

Having reached the quarter-century milestone, Sónar’s organisers united a cast of returning innovators with a broad selection of debut performances, reaffirming the event’s status as one of the world’s most crucial and forward-facing experimental music events.

Thursday belongs unquestionably to Little Simz and Yaeji, two artists whose rapid upward trajectory is neatly demonstrated by the crowds each drew to the SónarVillage stage, tempting substantial numbers of punters from the shade into the blazing late afternoon sun. Simz cuts a commanding figure on the stage, exhorting the sound engineers to turn her up as she struts her way through Bad to the Bone and Picture Perfect, and Yaeji kicks things up a further gear with a hi-nrg DJ set of house and acid techno complemented by modulated live vocals. Yaeji is infectiously fun to watch and as she drops into back-to-back renditions of Raingurl and Drink I’m Sippin On it’s wall-to-wall smiles in the Fira de Barcelona.

Come Friday the impossibly nice weather that prevails all weekend makes tearing ourselves away from Distruction Boyz’s propulsive Gqom set a tough call, but the blacked-out SónarDome is quickly filling up for one of the weekend’s most highly-anticipated performances: SOPHIE. There’s an undeniable sense of moment to the performance – SOPHIE is appearing on the day of her album release, and her explosive, exhilarating stage show feels like an exclamation point in what’s been her biggest year to date. Razor sharp and expertly choreographed recitals of Ponyboy and Faceshopping are as overwhelming sonically as they are visually thanks to the venue’s pummelling sound system, and Immaterial descends into a full-blown dance party.

Sónar readily eschews the linear techno-til-late approach to after-hours programming adopted by many of its predecessors, and there’s just as much variety to the night-time line-ups as there is the day. Yung Lean’s energetic stage antics impress early on Friday night, as do Bicep whose high-sheen live set draws an enthusiastic crowd of fist-pumping Brits. Despite being sandwiched between Bonobo and Diplo, Spanish DJ and producer Alizzz does well to maintain energy levels throughout his set with a breakneck mix of pop, trap and RnB. It’s left to Helena Hauff to close out the final slot on the opening night which she does with characteristic mercilessness.

LCD Soundsystem’s cinematic tendencies worked well in the cavernous SónarClub – with James Murphy on commanding form despite manning Despacio for three consecutive days – as does Thom Yorke’s impressive A/V performance with longtime collaborator Tarik Barri. Even the artists perhaps accustomed to more intimate spaces hold it down. Octo Octa’s alternates between tougher rave tracks and more jubilant numbers such as Fleeting Moments of Freedom (Woo), and Objekt and Call Super are both on typically flawless form (the latter, perhaps feeling a little sentimental drops an acapella of The Streets’ Weak Become Heroes mid-set.)

As the sun rises on the Sunday morning of Sónar punters scatter in different directions – to the beach, to one of the myriad afterparties taking place across the city, or sensibly to bed, to refresh for the evening’s closing concert with Ryuichi Sakamoto and Alva Noto. It may sound a little hackneyed but the depth and breadth of programming at Sónar is such that you could attend the festival innumerable times over and have an entirely different experience. Fortunately Sónar’s 25th edition was a statement of intent as much as it was a victory lap – its commitment to pioneering music and art remains as strong as ever, and with attendance apparently exceeding 120,000 throughout the week its longevity seems guaranteed.