eyed3
Read and manipulate metadata of MP3 files.
TLDR
View information about an MP3 file
$ eyeD3 [filename.mp3]
Set the title of an MP3 file
$ eyeD3 --title "[A Title]" [filename.mp3]
Set the album of all the MP3 files in a directory
$ eyeD3 --album "[Album Name]" [*.mp3]
Set the front cover art for an MP3 file
$ eyeD3 --add-image [front_cover.jpeg]:FRONT_COVER: [filename.mp3]
