As the user executes a performance on a preliminary or trial basis, performance data based on the user's performance are evaluated, a performance tendency of the user is extracted as a result of the extraction, and then, performance tendency information, indicative of the extracted performance tendency, is generated. Psychological state, such as a mood or feeling, of the user is detected from the performance tendency, and feeling information, indicative of the detected psychological state, is generated. Then, tone color control information corresponding to the generated feeling information is acquired from a storage section, such as a "mood/feeling" vs. tone color control" correspondence table, the acquired tone color control information is delivered to a tone generator, and desired tone color parameters are set on the basis of the tone color control information. The thus-set tone color parameters will be used for tone color control of performance data generated as the user subsequently executes an actual, formal performance.