http://www.mp3-box.org/convert-mp3-to-aac-mac/
On a MAC, if I convert a song in itunes from a mp3 to AAC, can my friend convert it back to mp3 on his MAC???
I need to compress to send through the email. I guess a AAC is commonly refered to as mp4? THANKS!
The short answer is “yes.” However, consider that every time you change formats, you are degrading the song somewhat. Also, consider that AAC files are generally smaller than mp3 due to the fact that they’re sampled at a lower bit rate. Apple claims AAC is a better format because 128 kbps AAC songs sound “just as good” as 192 kpbs mp3s, but your ears are the best judge.
how to convert iTunes DRM protected aa files to mp3, wma, aac formats on mac OS.flv