A lot of early-enthusiasts got BURNED and lost their collections of iTunes "licenses" early-on when this happened (since they insist that you don't pay for a copy of the music, only a license to play the music that they own).
For whatever reason, their computer gagged and iTunes crashed and lost its license file, even though all the songs were still saved on the (separate) iPod. If you just hook up the iPod and sync it, iTunes will erase all the music on it--and Apple won't let you re-download the same songs for free again. They'll just tell you to pay for it all again.
You will have to find third-party (illegal, according to Apple) programs to save off the music that is still on the iPod. iTunes wil not do it--Apple refuses to put that feature in.
Don't pay for music--download it for free. The ONLY reason for having DRM is to be able to re-charge you for using the same thing over and over.
Remember the DivX disk players!
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