Wav is (normally, unless already corrupted) an uncompressed, lossless, audio format. The OP's statement was a little off, but the premise is correct.
Mp3 is lossy. Many audiophiles and audio engineers argue that Mp3 actually sounds better (the compression gives the drums a "crunch" not normally present), but the point is you can go from WAV to Mp3, but you can't go back the other way around. Apple is irrevocably damaging some of his files.
> Many audiophiles and audio engineers argue that Mp3 actually sounds better (the compression gives the drums a "crunch" not normally present)
Quote please! Don't specifically mean it as a challenge to you, but as a musician, composer, and audio engineer (I'm not sure I identify as audiophile since that has baggage, but I know friends who do) I have never heard such a thing even mentioned and have a hard time believing there are serious engineers that think this.
The data reduction in the MP3 algorithm is designed around the frequency masking principles of human hearing[1] (EDIT: Spelling and citation), this technique can lose a lot of data with a small impact on perception when applied to harmonic sounds. Enharmonic sounds (e.g. is where the MP3 algorithm falls down); as I said, I've never heard any engineer say they think this sounds better.
Again, I don't say this to argue, I'd just be curious to know what these unicorn engineers have to say about this.
Mp3 is lossy. Many audiophiles and audio engineers argue that Mp3 actually sounds better (the compression gives the drums a "crunch" not normally present), but the point is you can go from WAV to Mp3, but you can't go back the other way around. Apple is irrevocably damaging some of his files.