For a content-prerecorded large capacity disc-shaped recording medium, a user interface having high flexibility is accomplished. Button image data, corresponding sound data as an effect sound, and control commands for the sound data and image data are multiplexed with a stream and recorded on the disc. A scenario reproduced from the disc is stored in a buffer 104. The image data and sound data are stored in a buffer 105. Image data is read from the buffer 105 in accordance with a scenario and expanded to a graphics plane 133. In addition, corresponding sound data is read from the buffer 105 and reproduced by a sound player 106D. When a button image is varied in accordance with a state change of the button, an effect sound is reproduced. As a result, a more effective user interface is accomplished.