A cordless telephone apparatus comprising: a portable handset; and a base station, the base station including: a first wireless communication unit (122, 124) which, in operation, is arranged to perform radio communication with a music player; a second wireless communication unit which is arranged to perform radio communication data with the portable handset; a control unit (109, 111, 113) which, in operation, is arranged to remotely control the music player via the first wireless communication unit (122, 124) when the second wireless communication unit receives first key information defined to remotely control; and a speaker (129, 130) which is arranged to output audio data; characterized by an audio processing unit which, in operation, is arranged to reproduce the audio data received by the first wireless communication unit (122, 124) from the music player and to output the audio data to the speaker (129, 130), wherein when the base station receives information regarding a defined key from the portable handset functioning as the operation unit to remotely control the music player, the base station is arranged to transmit remote control information to the music player, wherein the remote control information includes directive information adapted to direct remote control of the music player according to the defined key, the directive information including information adapted to direct a play procedure, a stop procedure, and a pause procedure of the audio data to the music player, and when the control unit receives from the portable handset second key information defined to adjust a volume, the control unit is arranged to control the volume of the speaker (129, 130) in the base station. a portable handset; and a base station, the base station including: a first wireless communication unit (122, 124) which, in operation, is arranged to perform radio communication with a music player; a second wireless communication unit which is arranged to perform radio communication data with the portable handset; a control unit (109, 111, 113) which, in operation, is arranged to remotely control the music player via the first wireless communication unit (122, 124) when the second wireless communication unit receives first key information defined to remotely control; and a speaker (129, 130) which is arranged to output audio data; a first wireless communication unit (122, 124) which, in operation, is arranged to perform radio communication with a music player; a second wireless communication unit which is arranged to perform radio communication data with the portable handset; a control unit (109, 111, 113) which, in operation, is arranged to remotely control the music player via the first wireless communication unit (122, 124) when the second wireless communication unit receives first key information defined to remotely control; and a speaker (129, 130) which is arranged to output audio data; characterized by an audio processing unit which, in operation, is arranged to reproduce the audio data received by the first wireless communication unit (122, 124) from the music player and to output the audio data to the speaker (129, 130), wherein when the base station receives information regarding a defined key from the portable handset functioning as the operation unit to remotely control the music player, the base station is arranged to transmit remote control information to the music player, wherein the remote control information includes directive information adapted to direct remote control of the music player according to the defined key, the directive information including information adapted to direct a play procedure, a stop procedure, and a pause procedure of the audio data to the music player, and when the control unit receives from the portable handset second key information defined to adjust a volume, the control unit is arranged to control the volume of the speaker (129, 130) in the base station.