Very good point! Songs compressed with lossless codecs represent exact digital clones of the originals (with regard to audio fidelity/quality.) Lossless formats: Apple Lossless (.ale), Monkey's Audio (*.ape), FLAC & I suppose Shorten for the more common lossless that use size reduction. I guess as high speed net connections & larger HDD's become more common we'll start to see more lossless songs being shared.

Some music encoded in mp3 really does show obvious loss of quality, be that loss frequencies or headroom. Yet some people swear by it. I suppose for heavy metal you're not going to notice much difference.