One of our clients just found an old iPod — this one looks like it’s 4th generation, from about 2004, based on Wikipedia’s iPod page.
These had actual hard drives inside, with moving parts, so after many years often the drives failed. However this one is still working! We were able to get all the music off for our client. The click wheel and black-and-white screen are still fun to use.
If you have an old one with a failed drive and want to see if you can get it working again, iFixit has guides for replacing hard drives on these old iPods. Here’s the one for the iPod 4th generation.