A portable telephone produces either beep sound or melody sound as incoming call
sound. The melody sound is produced based on music data, which are stored in advance
or downloaded from the prescribed distribution center, wherein the music data represent
the melody of a single musical tune in different arrangements that are respectively
assigned to time zones in advance. Hence, the portable telephone produces the same
melody in different arrangements in response to time zones, to which the time for
receiving an incoming call belong.