Music From iTunes doesn't Sync to iPhone?

I recently burned a CD of mines to iTunes. They're all check marked and appear in my iTunes Library and play just fine. However, when I click "sync," it doesn't show up on my iPhone.
Does anyone know how to fix that?

Man, this is a tuff one, as iTunes really doesn't make as simple as they should. Also aren't as open to input as the make themselves seem. There ae a few things. Is everything updated as much as possible? Did you jailbreak/homebrew? I doubt you did so I'll answer as best I can as if you didn't.

When your phone is plugged in, check the spot where you choose what to sync. The horizontal tabs. I forget where exactly. Make sure that it's selected there to be synced. And because iTunes isn't flawless as they make it out to be, go to the section in your library, and recheck to see if everything new you want is still selected. Another way to do it, is select the sync by band. That'll sync everything by the band… "artist" it's crude, but should get you what you want. Then there's, if I remember correctly sync new music. All this should be in the well under the same tab.

I don't use it, but there's cloud. Could give that a try. I recommend as a last ditch effort though. Best of luck