ITunes will not sync songs onto iPhone, troubleshooting methods not working

Question

Simply put, songs will not download onto my iPhone.  I have tried every method that I could think of to solve this:
-restarting phone and mac
-updating iTunes
-taking off all the music from the phone and redownloading
-rechecking the little check thing that says I want that song
-restoring my phone
-going onto the individual tab to sync and syncing from there(which leads to a whole other problem, because that deletes songs(story for another thread))
-manually dragging songs onto my phone icon dropbox thingy
-making sure the songs are the proper files
... and still nothing has worked.
When I go on my phone menu when its plugged into iTunes, and then go to the 'On Device' section, it shows that the songs are there, but they are faded out with this little circle thing next to them(I don't know if this is significant).
I'm at my wits end, I just don't know what to do.  I don't understand why iTunes is refusing to do something as simple as sync songs.
Any ideas? Thank you for any help you can provide!

Answer 1

UPDATE:
I finally figured it out (though I'm not sure this counts as 'figuring it out'). 
So, what worked for me was unchecking the check box thing next to the song and syncing the phone.  After the sync--behold!--, the songs were in my phone.  I don't know if this is another glitch or not, but I'm running with it.
I wanted to post the answer so that other people who may have had this issue can hopefully resolve it.