This deposit contains the Music, Heritage, and Policy in the Age of AI: Building the Diversity Pillar of the European Music Observatory with Federated Knowledge Graphs deliverable. The document reports on methodological, technical, and governance work carried out within the Open Music Europe (OpenMusE) project, focusing on federated cultural data infrastructures, diversity-aware policy indicators, and privacy-preserving evaluation methods for music ecosystems. It draws on national implementations (Slovakia, Hungary) and community-curated heritage data spaces (Finno-Ugric repertoires) as applied case studies. Disclaimer This is a draft document made available in accordance with Open Policy Analysis guidelines. It has not been formally reviewed, approved, or endorsed by the European Commission but it was approved by OpenMusE consortium partners. This document represents the version of the deliverable handed over by the Work Package lead to the project Coordinator for submission. It has not been reviewed by the European Commission or the European Research Executive Agency and does not represent an approved or final EC deliverable. The deposit is made in accordance with the Horizon Europe transparency requirements and the Open Policy Analysis guidelines, in order to ensure traceability, reproducibility, and a clear audit trail.