Itunes will not import music without having to delete all my previous ones?

Itunes will not import music without having to delete all my previous ones?

Added (1). I have previously used my Itunes to import music onto my iphone 6, but currently when I connect it the program recognizes my phone but will not let me sync music without deleting all my songs first. I'm on the same computer btw.

Either on your phone, on the computer, or BOTH, somehow you checked a sync setting that does this. I HATE that! I do "only sync checked music" - and today, I STILL had an issues with something that I had parked in the Cloud, and it was So stubborn about not wanting to leave ( "But you said you wanted me FOREVER - so you put me in the Cloud - and I'm telling you that I'm NOT GOING!") Technology is great when it obeys us - and we understand HOW to make that happen - but sometimes it turns on us like HAL the computer "I'm sorry, Dave - but I can't let you back inside… "

So DO NOT plug the phone into the computer - yet. Go thru thru phone a make sure that YOU are in manual control of what you want to sync - not thru the air, cable only, ONLY what you want. Then do the same in iTunes. THEN AND ONLY THEN, plug the phone in. Say a prayer or incantation of your choice. Be prepared to do this more than once, sadly - the phone/computer stuff, AND the praying part.