Using my Dads music on my iPhone?
There is no 'official' way to pull music from any iDevice back to a computer, but there are many unofficial apps that can do it.

The basic idea is that you get the music off the iDevice &amp; into iTunes, from where you can then keep it or re-sync it to your own device.

I know of no way to do this directly from phone to phone, you must have a computer as an intermediary.

Googling "copy music from iPhone to computer" will give you more variants on applications than you would know what to do with - &amp; also I don't know what computer platform you have, so I'm linking to a LifeHacker article explaining how to do it on Windows, Mac &amp; Linux.

How to Copy Music from Your iPhone, iPad, or iPod touch to Your Computer for Free