The Feasibility study for the establishment of a European Music Observatory (in short: EMO Feasibility Study) has identified four critical data gaps related to the diversity and ciculation of European music. This is a key business planning and policy problem, and of course, a serious shortcoming for better music research in the Europe. • The SME dominated music ecosystem of labels, publishers, concert promoters, tour managers have no clear understanding of the market opportunities in the Single market. • Cultural policies that were relying on quota-based local content regulations and direct diversity targets in public broadcasting are powerless in a streaming dominated music scene. • There are very few public data sources available for researchers and for educators. This document has three parts: I. Filling the Data Gaps The identified data gaps of the EMO Feasibility Study : 1. Cross-border activity on radio stations 2. Cross-border activity on streaming platforms 3. Origins of songwriters behind the most popular songs—however, in our view, this should not be limited to the most popular songs! 4. Cross-border circulation of artists via live shows 5. Planned tasks II. The Diversity & Circulation Pillar of the Digital Music Observatory 1. Cultural and Music Policy Relevance 2. Methodology Issues 3. Open Collaboration, Open Policy Analysis, and Open Data III. References