Our ambition with the development of the Open Music Observatory is to provide the technological basis and a practical roadmap for creating a European Music Observatory in a bottom-up, decentralised way. Instead of waiting for a central agreement on what a European observatory should collect or who should govern it, we propose a pragmatic approach: any data owner or institution that meets shared quality, provenance, and cooperation rules may contribute to an Open Music Observatory; once the system reaches sufficient maturity for European use, its long-term institutional form can be decided. Creating the Open Music Observatory is a cornerstone task of the OpenMusE project. This task is running till the end of the project (31 December 2025) with the collection, processing, and dissemination of more data and providing innovative, new data services in line with our exploitation pathways. This report is an accompanying document for the creation of Open Music Observatory as a digital infrastructure on the World Wide Web. The Observatory currently consists of four federated data modules: the Slovak Comprehensive Music Database, the Hungarian Music Database (GitHub) and the related Zenodo item. the Finno-Ugric Data Sharing Space, and the Open Music Europe Core Module accessed via the temporary landing page. Together they demonstrate how a decentralised, interoperable European music data ecosystem can function in practice. The Open Music Observatory operates as a digital service provider for the music sector, following the principles of the European Interoperability Framework (EIF) and using a governance model tailored to the distributed, cross-domain nature of music data. Its architecture and workflows draw on established European examples while introducing new methods for semantic interoperability, federated governance, and reproducible policy evidence. For the policy alignment of our plans, please refer to the A Green Paper on AI, Data Governance, and Metadata Policies for Europe’s Music Ecosystem. Practical Steps Towards a Decentralised and Open European Music Observatory (Zenodo link) which explains alignment with EU policies and the recomendations of the first CITF report.