A music reproduction apparatus (EM) includes: a reproduction section (RP) for reproducing user-selected music piece data; a generation section (SP1) for generating control information including music piece information identifying a music piece to be reproduced and reproduced position information indicative of a position, reproduced by the reproduction section, of the music piece data; a modulation section (SP2) 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 (13) for transmitting to outside the audio signal generated by the modulation section. An information processing apparatus (DS) includes: a storage section (STd) storing a plurality of sets of displaying content; a reception section (7) for receiving the audio signal; an extraction section (DM, EX) for demodulating the control information included in the received audio signal and extracting the music piece information and reproduced position information included in the demodulated control information; and a display control section (CTd) for identifying one of the sets of displaying content, stored in the storage section, in accordance with the extracted music piece information and displaying a part of the identified displaying content in accordance with the extracted reproduced position information.