Adding someone else's music to iTunes

One big problems with the digital age is legacy. You cannot transfer content between accounts. The only 99% above board way to do this, particularly if he had older purchases that are DRM protected, would be to authorize your computer to his account (which I am guessing there is some fine print saying you are not supposed to do unless it is your account -- no inheriting accounts) and transfer or re-download past purchases. Of course people don't think to include userIDs and passwords for accounts in their documents for others to use. I am sure the media companies (and those who sell media for them) absolutely love this because it is no longer as simple as inheriting a stack of CDs and basically means people end up buying it all again if it is a family standard.

You can transfer media from an idevice using third party software but anything with DRM protection will require the computer be authorized.

iTunes Store: Transferring purchases from your iOS device or iPod to a computer - http://support.apple.com/kb/HT1848 - only purchases from iTunes Store

For transferring other items from an i-device to a computer you will have to use third party commercial software. See this document by turingtest2: Recovering your iTunes library from your iPod or iOS device - https://discussions.apple.com/docs/DOC-3991

1) Why can't you share your Father's playlists ( if needed, create playlists on your Father's iPod then share to your device )

2) You can also email (from iPod) each song individually to your device