An acoustic system for use with a communication device, the acoustic system comprising: • an output unit (53, 55) configured to output (a) a sound, which is a musical piece, and (b) an image, which shows words that are lyrics for the musical piece; • a communication unit configured to wirelessly communicate with the communication device, so as to receive from the communication device: (i) a reproduction signal for musical piece data, and (ii) a reproduction position signal representing a reproduction position, in the musical piece data, of the sound outputted on the basis of the reproduction signal; • a counter for output control of the image, wherein the counter is configured to count a reproduction period of time; • a first output control unit; and • a second output control unit; wherein the first output control unit is configured to wirelessly receive, from the communication device via the communication unit, the reproduction signal, and wherein the first output control unit is configured to respond to receiving said reproduction signal by causing the output unit to output a sound based on said reproduction signal, so as to perform reproduction of the musical piece as represented by the musical piece data; and wherein the second output control unit is configured to wirelessly receive, from the communication device via the communication unit, the reproduction position signal, and wherein the second output control unit is configured to respond to receiving said reproduction position signal by causing the output unit to output an image on the basis of the reproduction position signal, said image being words which are lyrics corresponding to the sound outputted by the output unit; and wherein the second output control unit is further configured to correct the reproduction period of time counted by the counter to a time corresponding to the reproduction position as represented by the received reproduction position signal, and wherein the second output control unit is configured to cause the output unit to output, as the image, lyrics corresponding to the sound outputted by the output unit on the basis of the reproduction period of time as counted by the counter. • an output unit (53, 55) configured to output (a) a sound, which is a musical piece, and (b) an image, which shows words that are lyrics for the musical piece; • a communication unit configured to wirelessly communicate with the communication device, so as to receive from the communication device: (i) a reproduction signal for musical piece data, and (ii) a reproduction position signal representing a reproduction position, in the musical piece data, of the sound outputted on the basis of the reproduction signal; • a counter for output control of the image, wherein the counter is configured to count a reproduction period of time; • a first output control unit; and • a second output control unit; wherein the first output control unit is configured to wirelessly receive, from the communication device via the communication unit, the reproduction signal, and wherein the first output control unit is configured to respond to receiving said reproduction signal by causing the output unit to output a sound based on said reproduction signal, so as to perform reproduction of the musical piece as represented by the musical piece data; and wherein the second output control unit is configured to wirelessly receive, from the communication device via the communication unit, the reproduction position signal, and wherein the second output control unit is configured to respond to receiving said reproduction position signal by causing the output unit to output an image on the basis of the reproduction position signal, said image being words which are lyrics corresponding to the sound outputted by the output unit; and wherein the second output control unit is further configured to correct the reproduction period of time counted by the counter to a time corresponding to the reproduction position as represented by the received reproduction position signal, and wherein the second output control unit is configured to cause the output unit to output, as the image, lyrics corresponding to the sound outputted by the output unit on the basis of the reproduction period of time as counted by the counter.