Syncing iPod to computer 2 without erasing new music

Solution 1:

senuti is the tool I usually recommend in these cases.

On the other hand, can't you just transfer the music from Computer 1 to Computer 2 directly?

Solution 2:

The music on computer 2 won't be erased but the music on the iPod will be erased. If this music was purchased through iTunes and all through the same Apple ID then they can be downloaded onto the computer through the iTunes store. For non-protected music on computer 1 you can just make a back up copy cd then load that cd onto computer 2. For any protected music you would need to make certain it was purchased through the same Apple ID and that computer 2 is an authorized computer under that Apple ID. Know more about how to transfer or backup music from iPod to Mac, which included the detailed tutorials of how to transfer or backup your music from iPod to Mac. Best wishes.