Why doesn't my MacBook recognize my iPod Shuffle?

I had some difficulty with trying to get my dad’s old iPod to work recently, and then it was disconnected while transferring data on accident and now my MacBook will not read it and it does not show in Finder. When I plug it into my MacBook is only flashes the orange light but I cannot play any music on it nor can I put any on it. How do I restore it to factory default if it does not show up in Finder/iTunes?