iPhone won't sync with my MacBook

Help! I recently bought a MacBook because my pc died. I used a third party software to transfer the contents of my iTunes libary to my mac as there was no other way of doing it.All seemed fine.This morning I put a couple of CDs into my iTunes libary, and when I came to sync, the mac & iPhone showed syncing for a couple of seconds, but the new contents I put into iTunes didn't show up on my iPhone.What am I doing wrong?

I think we will need some more info. Does that mean you already had music on there and it is still there after syncing? What options are checked when you have the iPhone attached to the MB and you have the phone selected on the left and then select the music tab? When looking at the new albums in the iTunes library are there check marks next to every song?

Yes, the songs are ticked, the mac is def authorized,songs still on mac & phone, phone selected etc. It just syncs for two secs & that's it.not enough time there for any changes to take place. A bit baffled.