I've been trying to figure this out and i'm going crazy and need help. My itunes on my new computer is for some reason super outdated and doesn't match my current iphone AT ALL. It has some, but not even close to all of my music. I have so much more music on my iphone that I have accumulated over the last decade. So I bought a new CD and ripped it into my itunes by now it won't let me move it to my iphone. If I sync my phone to my itunes the only available options will wipe my phone and match it to my current itunes (which as I mentioned doesn't have a ton of the music found on my iphone). Help please!
Read more: https://iphoneus.org/faq/igive-up-with-this-itunes.html