Complexity

☀️With the first names for Complexity Fest 2026, we’re pulling out all the stops: from the physical precision of snare-drum soloist .kiyasu in an alternative space within the building, to the rhythmic whirlwind of Venezuela’s , locking prog and post-hardcore tightly together.
Italy’s .music brings over twenty-five years of underground experience and returns with new material that sharpens their heavy, uncompromising sound even further. celebrates ten years of Complexity with the next phase of their rave-meets-black-metal universe, armed with new work and an audiovisual approach that takes full control of the room.
And then there’s performing in the Netherlands for the first time: Korean screamo built on long tension arcs, raw outbursts, and a cult status that stretches far beyond their borders. Five acts, five distinct worlds, one festival bringing it all together.

More to be announced!

🎫 Get your early bird tickets until Monday match 6th before 12:00

Complexity Fest 2026: Ryosuke Kiyasu, Zeta, ZU, Violent Magic Orchestra, Hollow Jan & meer - Patronaat Beleef Complexity Fest 2026 op 15 aug in Patronaat Haarlem: het festival voor avontuurlijke, grensverleggende heavy muziek met internationale acts en innovatieve sounds.

We are very much looking forward to see, hear, witness showcasing their immersive eclectic sound pallet in which we hopefully get a glimpse of the new album that is released on the 3rd of October. Even better is welcoming back .stepmother after their hypnotic show on the mainstage at Complexity Fest 2024. Don't miss out on this one we'd say you!

🍻 After ECHT!’s set, the night isn’t over just yet. From 23:00 onwards, we invite you to head over to the Anti-Bar, just across the street from Patronaat. It’s the perfect spot to grab a drink, catch up with friends old and new, and talk through your favorite festival moments.

📍Zijlstraat 21, Haarlem

🥘 At Complexity Fest you won’t go hungry. Two amazing caterers will keep you fueled: ABSEA Foodtruck brings fresh, colorful streetfood with a comfort twist, while Eef & Lien serve up vibrant, plant-based dishes full of flavor. All options are vegetarian or vegan!