To properly transmit and receive without generating sound interruption a sampling waveform data required in a real time from one device to the other device between the two devices connected via a communication means.

In a key board device 100, a CPU 1 reads out a sounded musical sound data of performing music from a ROM 4, requires to a data base device 200 through a communication interface 7 the transfer of the musical sound data and a sampling sound waveform data corresponding to a tone color data set by a switch part 3, and assigns a data density of the transferred sampling sound waveform data to be either of a standard sampling sound waveform data or a compressed sampling sound waveform data, in response to the condition of the performed music.