The apparatus of the present invention improves training efficiency, and monotonous repetition of training is avoided. A unit acceptance judgment section (4) judges whether all performance of the units in the current rank have reached an acceptable standard or not. When all performance is accepted, a unit in an upper rank is designated. The performance data in the designated unit is read from a performance data storage (7) to a key depression instruction generator (8), and a key depression instruction is displayed based on the performance data. When only a part of the unit in the current rank is acceptable, a unit updating instruction is output to a lesson menu display (14), to thereby display that the unit subsequent to the currently designated is the unit to be played next. When the unit is updated, the unit having the same note information as that already accepted is not designated.