There is provided an apparatus for processing at least one MIDI signal. The apparatus includes a first input for receiving MIDI signals, a second input connected to an audio output of a sound generating device for receiving analog signals, a digital-analog converter coupled to the first input for converting the MIDI signals into analog signals, and a summing circuit for summing the converted MIDI signals from the first input and the analog signals from the second input. A resultant signal from the summing circuit may be output from a connector of the apparatus. The connector may be for connection to a sound reproduction apparatus. Preferably, the first and the second inputs allow input of signals either by a wired connection or wirelessly. There is also provided a corresponding method for processing data from a sound generating device.