In an ensemble performance, performance lesson or the like, a musical score (display content) is displayed and input audio is recorded. The input audio includes notes, comments or the like uttered by a human player or an instructor. During recording of the input audio is received a user input designating a desired time position on the musical score displayed on the display device. A recording time of the input audio based on a time point at which the user input has been received and the time position on the musical score designated by the user input are stored into a storage device in association with each other. An icon is displayed in association with the time position on the musical score designated by the user input. Once the icon is selected, voice based on the recording time recorded in association with the icon is reproduced to sound the comments, etc.