And you could use far too many apps, I can't guess what player app you used. As you know by now the concept of cover art is there but there are so many standards that you find yourself researching which player app and then how to get cover art over and working,.
So I used a program to find cover art for every single song on my computer. Since it was a manual program, it took awhile. Whenever I click on the music file, the thumbnail of the cover comes up. Then I copied the files onto my Samsung Galaxy 4.2. I could still see the cover thumbnail in the folder on my computer. I disconnected from the computer, and only a couple of my songs had the correct album cover. The rest had the same cover album as one song. I deleted that one song, but all the songs still have that cover. I also have some songs that were ripped from a cd, they are working perfectly. What went wrong? Am I using the wrong size or file type for the cover art, or does that not matter?