How to sync phone to (new) computer and keep everything on it the same?

Question

I want to put music onto my iphone (the music is on my laptop, and on itunes).
When I connect my iphone to my laptop it asks me to set it up as a new iPhone.
I cannot risk losing any of my data on the phone (eg. contacts, messages, notes, apps, etc).
The phone is connected to my icloud account, and everything is checked to be saved on icloud.
On the computer there is no option to restore from the icloud account.
Do I restore from the icloud account via my phone (and then will it sync the music onto my phone via computer?)? Or set it up as a new iphone via my laptop?
The end result I need to have is for the phone to remain the same (apps, information, contacts, etc.), except with my music (that is on my laptop) playable in the music app.
Thanks so much in advance for any help that could be given!

Answer 1

This is assuming all the music on your  iPhone is from iTunes, if not, get iTunes Match.
When your phone is connected to the computer, right click the icon of your phone under "devices" and choose "transfer purchases"
This should pull everything you have from the app store/iTunes store on your computer
Transfer pictures over manually using image capture, iPhoto, or from your autoplay option on a windows computer
Once everything on your computer matches your phone, you can go ahead and sync
Whenever you sync from the computer, remember that "syncing" pretty much means your phone will mimic the computer
iCloud will back up your text messages too. Don't worry. If you want to go the iCloud route, your music on your computer would either need to be iTunes purchases or you need to be using iTunes match.
To restore from an iCloud back up, you'd have to erase your phone by going to settings>general>reset>erase all content and settings and choose "restore from iCloud back up" when the phone prompts you. Note: this will restore your phone to factory and kick it into the set up assistant, so triple confirm that iCloud user in
I'd recommend the easy route and just getting your computer's music coded over to iTunes purchases  (with iTunes match) if it isn't already. That way, you can just download it on your phone through the iTunes app.