Here's another simple yad gui I put together to edit metadata tags on media files including adding and removing lyrics and cover art for various formats. You obviously need to have yad installed as well as ffmpeg and ffprobe to use this program. If metaflac is installed that will be the default for flac files. If you want to modify tags of ape or ac3 you will need the apetag program installed. Cover art options for m4a files require AtomicParsley, mp4art, or mp4tags. Cover art options for wv (wavpack) files requires wvtag.
0.5 bugfixes
0.6 bugfixes
0.7 bugfix
0.8 improvements + bugfix
0.9 improvements
1.0 bugfixes and improvements
1.1 Changed remaining file choosers to drag and drops and got rid of the gtk buttons
1.2 code clean up