I FOUND A SOLUTION! For clarification I will sum-up the orignal problem and then what I did to correct it.
The Problem:
1) I downloaded iOS7 over the air (OTA) via wifi.
2) When viewing my artist list in Music, some artist profile pictures that displayed a random album cover for that artist in iOS6 were now replaced with a picture of the artist; origin from Apple. Whether I had multiple albums for an affected artist or only one mattered not. For instance:
a) AC/DC, 13 albums with album art, 0 albums without album art. Result: picture of them onstage, not part of any album cover, pushed by Apple.
b) Adele, 1 album with album art, 0 albums without album art. Result: picture of her looking into a mirror, not part of any album cover, pushed by Apple.
The Solution:
1) Download the latest iTunes. Connect the affected iPhone to the PC/Mac using the cable. Back-up the iPhone.
2) Restore the iPhone back to factory specs. This will replace the OTA "version" of iOS7 with a non-wifi pull from Apple "version" of iOS7. This will totally wipe the iPhone clean and put in in a state as if you just bought it; hence the above needed back-up.
3) When step 2 is complete, you will be given a choice to set-up your iPhone (as if you just bought it) or restore a previous back-up. You want to choose restore back-up.
4) This should remedy the problem with one minor issue. I'll purchase songs from Am--on.com from a "Greatest Hits" album but use the original ablum art of the songs. Now the "greatest hits" cover shows and I am sure that it's because the art is embeded in the song's metadata and it is an easy-peasy fix and has nothing to do with any unauthorized pushing of album art. So....hope the above works for you because it sure worked for my 8,300 songs.