If you convert your AAC files to MP3’s with Itunes, your Clip won’t recognize them due to proper tag issues. The Clip will dump everything into “Unknown” album folder. You can scroll files under Songs only. No artist or album folders!
I am not sure whether or not the newest version of Itunes software does the conversion properly. (remember, the windows explorer will show the album and artist folders, not the Clip!)
However, there is a great solution. With free software http://bonkenc.org/ you can convert AAC files with proper tags. I did it. Now, my Clip recognizes artist and album names. That’s how I enjoy listening to music, picking albums on List.
Make sure you read FAQ’s on this site to make changes such as bit rate. Just save your new mp3 files in a different folder.