An electronic device, data processing method, data control method, and content data processing system enabling a user to search for a track reproduced in the past, but with a forgotten title name and an artist name. A CPU displays on an LCD panel a reproduction history screen displaying a number of tracks reproduced that day on a calendar. By a user operation via an input device, the CPU switches the reproduction history screen to another reproduction history screen displaying a list of tracks reproduced on a certain other day as the reproduction history list. It reproduces the track selected by the user and allows editing of its attribute.