What they should do is offer all their customers to redownload the music they bought without DRM, and keep that server up for at least another year. Or make a tool available to clear the files of DRM, without re-encoding them.
B.t.w. has nobody cracked their DRM? That would be the way to go if you wanted to keep the quality of your music files.
B.t.w. has nobody cracked their DRM? That would be the way to go if you wanted to keep the quality of your music files.