Well, I suppose it's not possible for me to redownload the music as it's not on the servers anymore. The music worked fine on my phone but I found this as I reinstalled my Mac and just redownloaded my music library. Everything except that one album was pulled down just fine. Perhaps there's a copyright dispute or something. I don't know but as it was all public domain music, I managed to put together a playlist comprised of 2 other albums I bought that contained some of the songs.