Downloaded music is usually in another format like MP3 for example. The files will very in size, based on compression and the bitrate used. 128kbps is normally the lowest I go for MP3's, as any lower and you start to lose quality. The higher you go, the better the quality, but the larger the file size. Many programs will allow you to rip the music in its native CD Audio format so you won't lose any quality, the file will be much bigger though, compared to MP3 or WMA. Also, it is illegal to download music if you don't pay for it, thought I'd let you know.
