My iPhone 5 won't sync with iTunes?

I get this error message: My iPhone 5 won t sync with iTunes

and I still have 9.73GB left. What is going on?

Added (1). I'm adding 3 songs. I doubt 3 songs is about 10 gigs

The size of the files you have selected exceeds your current available space (i.e. 9.73gb)
Try to find out the combined size of the files you have selected and if it exceeds 9.73gb then you have to decrease the number of files you have selected so far…