A music reproduction apparatus includes a reproduction section for reproducing user-selected music piece data, a generation section for generating control information including music piece information identifying a music piece reproduced by the reproduction section and reproduced position information indicative of a currently-reproduced position, a modulation section for outputting, on the basis of the generated control information, an audio signal of a predetermined frequency band for carrying the control information, and an output section for transmitting to outside the audio signal generated by the modulation section. An information processing apparatus stores a plurality of sets of displaying content, receives the audio signal, demodulates the control information from the received audio signal to extract the music piece information and reproduced position information, identifies displaying content from the extracted music piece information, and displays a part of the identified displaying content in accordance with the extracted reproduced position information.