Why can I not sync my songs in my iPhone?

I'm dragging songs to my iPhone but it won't let? I have a lot of empty storage as well and it still just won't take the songs, please help?

Q: Why can I not sync my songs in my iPhone?
A: Because you don't know what you're doing.

Is the iPhone synced with your computer? If so, on the main page make sure the "Manually manage music and videos" is checked.

  • Why won't't songs sync to my iphone 4s? My iphone and itunes have up to date software and this past time when I synced my phone some songs that were already on my phone now skip and show the still downloading circle and songs from my new CD won't upload to my phone at all. I've tried restarting the phone, deleting/readding songs, etc and nothing has worked.
  • Why won't my iTunes let me sync my songs? I have restarted my laptop, un-installed iTunes then reinstalled it again several times. And after I do any of them I will plug my iPhone 4S into the USB (with cable) port and it'll start syncing my music but then a notification will pop up and say my music can't be found. But all my music is still in the iTunes. I don't get it?
  • Why is it that sometimes i sync my iphone some songs get deleted for no reason? Sometimes when i sync my iphone (especially when i sync a lot of songs) other songs just seem to disappear from my iphone and i have to re-add them to my library to get them back on my iphone. Why does it keep doing this?
  • Why doesn't my iphone sync new songs? I have songs in the library waiting to be synced, but whenever i click file on top of itunes, the sync option is gray? Why can't i sync new songs even if they are in my library?