McBluna 
tinyMediaManager is a media management tool written in Java/Swing. It is written to provide metadata for the Kodi Media Center (formerly known as XBMC), MediaPortal and Plex media server. Due to the fact that it is written in Java, tinyMediaManager will run on Windows, Linux and macOS (and possible more OS).
https://www.tinymediamanager.org
Mp3tag is a powerful and easy-to-use tool to edit metadata of audio files.
It supports batch tag-editing of ID3v1, ID3v2.3, ID3v2.4, iTunes MP4, WMA, Vorbis Comments and APE Tags for multiple files at once covering a variety of audio formats.
Furthermore, it supports online database lookups from, e.g., Discogs, MusicBrainz or freedb, allowing you to automatically gather proper tags and download cover art for your music library.
You can rename files based on the tag information, replace characters or words in tags and filenames, import/export tag information, create playlists and more.
https://www.mp3tag.de
Mp3tag is a powerful and easy-to-use tool to edit metadata of audio files.
It supports batch tag-editing of ID3v1, ID3v2.3, ID3v2.4, iTunes MP4, WMA, Vorbis Comments and APE Tags for multiple files at once covering a variety of audio formats.
Furthermore, it supports online database lookups from, e.g., Discogs, MusicBrainz or freedb, allowing you to automatically gather proper tags and download cover art for your music library.
You can rename files based on the tag information, replace characters or words in tags and filenames, import/export tag information, create playlists and more.
https://www.mp3tag.de
