Robbin's team, which included Apple interface designer Tim Wasko, would create the high-level user interface and music playing software in the iPod, as well as the version of iTunes that would sync with the iPod at launch.

Both teams put in long hours creating the device: 18 to 20 hours a day, seven days a week, according to Fadell, which took such a toll on his personal life that his girlfriend broke up with him.

While developing the iPod, Apple used a shoebox-sized prototype that enabled easier debugging while also obscuring the ultimate size of the device. Even within Apple, not everyone was certain of all the iPod's intended characteristics.

And what characteristics it would have. As with all its products, Apple wanted the iPod to stand out visually. While the software and hardware teams chugged away, Jonathan Ive's industrial design group got to work crafting the exterior appearance of the iPod.