i reimaged my mac and want to import the music from my ipod classic back to the mac. when i plug it in, it sees it but just says "loading" forever. how do i get the music from my ipod classic to my mac?

my Mac is over 10 years old so I purchased a new hard drive for it which cleared everything (it was not backed up). now, iTunes doesn't show the music that I previously had on there but that music is on my iPod classic. how do I get the music from my iPod classic back to my Mac? I'm afraid if I sync, it will delete the music from my iPod with no music. help