This presentation introduces an ongoing initiative to extend the Linked Art ontology in order to address the specific documentation and analytical needs of the performing arts. Developed within the ERC-funded STAGE project (From Stage to Data, 2024–2028), the work engages with core modelling challenges inherent to live performance: event hierarchies, role attribution, and the documentation of ephemeral practices. Drawing on CIDOC CRM as a top-level framework, the proposed extension has been tested across multiple use cases derived from the Festival d'Avignon archives. The presentation will outline the semantic models developed, the methodological approach adopted, and the international expert group involved in the process. The extension is now entering a phase of community review and validation, and we welcome feedback and collaborative engagement from the SIG.