How to put music in my itunes into my iphone 4s?

My itunes and iphone 4s all up to date etc. I tried sync but it just downloaded the apps no music. Can someone please tell me what i'm doing wrong?

Plug in your iphone 4s, on the phone button (it has your name on it and a charging icon). Click that.

A menu will appear in the middle of the screen, click on the tab about Music and ensure you are syncing music.