From the blog "Emby Blog"

Emby Server 4.6 is currently rolling out. Here are the highlights. Rewritten Music Scanning This 4.6 release will rescan your music library. We apologize if this causes any inconvenience. This solves a lot of our previous music-related shortcomings, specifically: Any folder structure now accepted, no matter how clean or dirty Albums are now fully tag driven and are no longer tied to folders Local metadata for albums will still be supported, and local metadata for