Audio data are played back by a personal computer a relationship with a playback process recognized easily. Displays showing the contents of play lists are arranged and displayed so that the contents become continuous in sequence in a playback sequence from content that is currently being played back from a display of an operation element that causes an image of a playback process to appear or from a display showing the content which is currently being played back. When the playback of one piece of content of one play list from among a plurality of play lists is terminated and one piece of content of an other play list is played back, at least the content that is currently being played back and content to be subsequently played back are displayed so that the contents can be distinguished.