Of all the music file formats, the MP3 file format manages to remain the most popular one, despite the fact that now much better audio file formats are available like the Vorbis OGG and the MPEG4 audio files. One of the striking features of the MP3 files is the ability to store non-audio meta information inside the file itself in the form of ID3 tags. Using these ID3 tags, you can store the basic information about music like the song title, album name, year of release, music genre and more. You can also store an album art (a picture of the music album) inside the MP3 files through the ID3 tags. When you play these music files in a media player or on your smartphone, then this album art is displayed on the screen.
If your MP3 music collection does not have any album art stored inside the ID3 tags, then you can easily find and add the album covers using the free disCoverJ software. In fact disCoverJ supports many other audio file formats too like the mp4, m4a, m4r, ogg, oga, flac, wma, ra. This software is designed using the Oracle Java and therefore you would need the latest version of Java Runtime Environment (JRE) installed on your PC.
The disCoverJ has a drag-n-drop software and you can just drop all of your music files (supported audio file formats only) on the disCoverJ window. After adding these files, you can see which of these files already have any album art. If the audio file has an album art, then you can remove it before searching for a new one. In order to search for album covers, you can just click on the big orange colored search icon near the lower-right corner. It can look for the album cover on a number of sites like iTunes, Spotify, Bing, Amazon and more.
When searching for the album covers, it looks for the search terms from inside the meta tags. So you must have proper meta tags set for the title, artist, album and the release year for the audio files before you can get an album cover image. I played around with an MP3 file and changed the ID3 tag to make the title and artist to “Lady Gaga – Batman Theme” which is obviously a bogus song. But disCoverJ was still able to find a Lady Gaga album cover for this fake song. This only shows that if you have wrong meta tag information stored inside an MP3 file then you will get a wrong cover for the song – you should correct the meta tags before using the disCoverJ software.
You can download disCoverJ software from https://bitbucket.org/rouven_h/discoverj/downloads.