Itunes sync problem

Hi

my problem is that i have 650 music foles in my itunes (pc) and when i try to sync it to my iphone (via wire) only 20 songs get synced and show on my iphone but rest show up on (my device) in itunes but not my phone and files that dont show up has an exclamation mark beside them which cannot be clicked or anything show up .

i have latest versions and same apple id also.