Syncing ipod to itunes

I have an iPod that has been in use for some time.

I now want to sync it to iTunes on my macbook pro so I can copy some songs from the macbook to the iPod.

when I connect the iPod to the macbook it comes up saying

welcome to your new iPod 

The only options are to set up as a new iPod or restore from a backup, neither of which are what I am trying to do.

is there are way to get this to work the way I am wanting? or is there an alternative way to get songs into the music section on the iPod without syncing with the mac?