I must admit total ignorance to all these music files and I'm embarrassed to ask this question. My daughter and I just downloaded a Sheryl Crow album. She wanted a cd so I copied the aac files to a cd for her. I thought I was making a mp4 or m4a cd, but, it copied as aiff files a regular cd! I don't know... just having a hard time understanding how this is accomplished. (an aac protected file to aiff).