Why does iTunes say that I have more songs in my iPhone 4 than I already do?

I have recently backed up my iPhone 4, then I restored it, and restored the back up now it says that i have 173 songs on my phone so I went to music on iTunes and clicked on Entire music library. I applied it and it says 438 songs on iTunes but it did not change on my phone, so i switched to Selected playlist and applied it again and the same thing happens when i keep switch it. I also tried to uncheckmark some songs and applied them, still it was the same. How do I get my songs back?? please help me

Thanks