Album Cover Display (Mp3s Edited?)

This question applies both to Windows and Mac...

For iPod classics and other iPods) that display album cover art, does anyone know whether, when iTunes retrieves those images in its library, it adds the jpgs as tags to the mp3 files themselves, or are they transfered to the iPod as stand-alone jpg files (invisible or otherwise)? I'd like to do the album cover option, but I don't want iTunes editing my mp3 files.

Any help would be appreciated.

I believe Album art is embedded in MP3s.

If you look in your iTunes folder, you'll see a folder titled "Album Artwork". Just to experiment, I opened iTunes and made a mental note of some albums that had artwork. I then moved that artwork folder to my Desktop, re-opened iTunes, and found that some of the music that had artwork now no longer didn't, but others still did.

After experimenting back and forth, what I've found is that the songs whose artwork disappeared after removing the folder were songs that iTunes had downloaded the artwork for. The songs that still had artwork were music *I* had added myself at some point, as well as songs that I've bought off iTunes.

So... bottom line... it appears that when iTunes downloads album art, it doesn't modify the mp3 file itself. It just associates the 2 inside the library database.