Originally Posted by quantum-x

Even if you're not an audiophile, here's why.
Say you encode all your songs at today's standard of choice, be it MP3, AAC, whatever.

6 months down the track, when the new audio player comes out, and you need to re-encode it, or you have new headphones / stereo and can hear the compression - if you don't have a lossless source, you're fucked. You transcode a lossy song, you get even more losses.

If you have the original, you can encode no issues.

Same thing as keeping the HQ photos you shoot, or the film you shoot, or whatever