Syncing with Multiple Computers

Is it possible to sync to more than one computer with Multiple iDevices?

I have all my devices synced to my Windows laptop which is still fast but I don't use it anymore since I switched to Mac this year. I tried to sync my iPhone 6 to my Mac a few months ago and I found out that apparently you can't, and to do so you need to erase the iPhone completely to sync, so I left it... Now I would like to sync my devices so I can sync apps and music from CDs that I purchased not through iTunes... I am hoping there is an easy solution to force the iDevices to sync to my Mac without erasing any of there data...

I am running the latest iOS on all my devices including iPad Airs, iPod touches and iPhones... The Mac I would like to sync my devices if possible is my MacBook Pro 2015 running the latest OSX.

If anyone can point me to a website or knows how to, it will be much appreciated!

Thanks in advance.