Why does iTunes want to delete my iPhone music?

Jan 2, 2012
5
0
1
#1
I've added 1 new music file to iTunes that I created (not purchased) and tried to sync it to the phone but iTunes wants to totally delete/replace everything on the iPhone with the iTunes library which doesn't include everything that's already on the iPhone. Does this question make sense ?
 

rambo47

Contributor
Silver
Apr 4, 2010
528
79
28
Northern NJ
#2
That's how all i-devices are set up. They associate with one library on a single computer. How did you get your music onto your iPhone? Was it with a different computer?