iPhone Synching

I have an iPhone 5C, running 8.1.2 Trying to synch phone with a Mac Power Book, running OS X Yosemite 10.10.1 and iTunes 12.0.1.26. Every time I try back up the phone & synch music, the process gets stalled at Step 7 of 8...downloading photos. In the past, the synching process took only a few minutes. This time the process has taken over 4 hours and still is not completed. Any suggestions? Thanks!