Based on music performance data, music score display data are composed for displaying a music score representing the music performance. A user inputs his/her musical skill to the apparatus. Referring to a musical skill level versus music score item correspondence table, music score items to be exhibited in the music score are determined to meet the musical skill as inputted by the user, and are included in the composed music score display data. Thus, a music score containing assisting as well as necessary detailed musical signs and indications which meet the user's musical skill will be displayed in addition to the main musical notation of the note progression.