Electronic keyboard musical instrument

An electronic keyboard musical instrument comprising:

• a sound board made of a vibratable plate member;
• a frame substantially following a periphery of the sound board, wherein the sound board is attached to the frame;
• a plurality of key operators;
• at least one pedal operator;
• a first performance signal generator for generating a first performance signal based on an operating state of the plurality of key operators;
• a second performance signal generator for generating a second performance signal, which is different from the first performance signal, based on operation of the plurality of key operators and operation of the pedal operators;
• at least one speaker for generating musical tones based on the first performance signal generated by the first performance signal generator;
• and
• at least one vibrating device mounted to the sound board for vibrating the sound board based on the second performance signal generated by the second performance signal generator,
• wherein the sound board is free of any speaker being mounted thereon, and
• wherein when the at least one speaker is driven to sound musical tones, the at least one vibrating device is also driven to vibrate the sound board.