If you have tunes to sync back to a computer, try iRip. Don't run it or connect without reading the instructions.
I'm trying to transfer all the data on my wife's iPhone 5 to her new 6s but the process is not as easy as I thought it would be. It seems Apple assumes that the iPhone user will be forever using one computer as the main iTunes computer. However, in this case, the original computer iTunes was installed on has been upgraded and no longer contains the iTunes library, so I want to first sync the contents of the iPhone 5 to a new iTunes library, then sync that library to the new iPhone 6s.