There is provided a musical tone control apparatus that enables a user to easily play a musical instrument without spoiling the user's feeling that he is actually playing a musical instrument. A storage device stores musical piece data containing interval data indicative of intervals of musical tones constituting a musical piece. A motion of an operator is detected. A controller provides control so as to instruct a musical tone output device capable of outputting musical tones to adopt the intervals as one of characteristic amounts relating to musical tones to be output from the musical tone output device, according to the interval data, and instruct the musical tone output device to adopt at least one of the characteristic amounts other than the intervals according to the detected motion of the operator.