how do i play mpeg 4 audio

im trying to move all of my audio file from my windows 7 laptop to my mac book but none of the files are working. They are MPEG 4 files but it wont play on my itunes or anything (when i play on GOM player it says that the file is corrupt). I have a crapload of music im trying to move onto itunes (More than 5 thousand ) i really hope theres an easy way to fix this