answer:Is your iPod already synced to another computer? It can only be synced to one at a time. Alternatively, is the software on your iPod up to date? If not, it can have problems syncing with iTunes. Also, go to Preferences > Devices and make sure that you have not checked the “Prevent iPods, iPhones, and iPads from syncing automatically” box. If none of these things work, you can still add music to your iPod manually. Syncing is just a more automatic way of doing things.