Sanatorium Merkurial is a collaboration between Sanatorium of Sound, the experimental music festival in Sokołowsko, Poland, and Merkurial, the artistic collective founded by Robert Piotrowicz and Jacek Sienkiewicz. It brings together distinct artistic practices that build their own musical languages beyond the dominant narratives of Western European avant-garde. A central concern is the changing condition of contemporary performance — especially the affective dimension of abstract music: its capacity to work through the body, intensity, tension, and the relationship between performer and audience. Affect lets music move beyond formal structure into social and political space. "Merkurial" evokes mercurial states — instability, transition, suspension between categories — where ambiguity and contradiction are deliberate choices, not problems to resolve. Transformation becomes the goal itself, letting new forms emerge. This expanded field turns abstraction into a physical, cultural and social experience at once. Rather than a unified aesthetic, the programme gathers distinct artistic languages whose common ground is ambiguity, transformation and affect — not stylistic similarity. The London concert starts a new collaboration between Merkurial and IKLECTIK, creating space for these positions to meet — reflecting a shared interest in practices resisting fixed classification, and listening that emerges through encounters between sound, space, technology and the body.