For those musics which are not identifiable, you can do the folllowing to make your own Album arts:
In iTune, clik on the music library. View the song in Grid mode. Click on the Album without artwork. Then on the bottom left corner of iTune, paste a suitably sized image file (I usually download those image from the net) As long as the picture covers the entire space here, it should look good (not blurred).
Do this for your Church musics, or your own recordings!