Music won't Go On My iPhone?

I have never had this problem before. So I have songs in my iTunes library that aren't on my iPhone, So I dragged them onto my phone. Then I went to my iPhone, and clicked on the music section. (where it says what songs are on the actual iPhone) It said that the songs are on my iPhone, but I looked on my actual phone, and they weren't there! The sync music box is already unchecked, and i don't want to check it because there's music that is no longer in my library that I want to keep on my iPhone.

Firstly, right click on your iPhone in iTunes and click "transfer purchases". That puts the music thats not in your iTunes library back into your library. Once you have done that, tick the "sync music" box and make sure "manually manage music and video's" is unchecked on the summary page. Sync your iPhone and all should be simpler and on your iphone.