A keyboard musical instrument comprising: a plurality of keys; a plurality of sounding bodies each provided in corresponding relation to each of the plurality of keys; a plurality of hammers each responsive to an operation of any one of the keys and adapted to strike the sounding body corresponding to the operated key; a stopper configured to be capable of preventing the hammer from striking the sounding body; a soundboard configured to be vibrated with vibration of the sounding body; an excitation unit including a vibration member connected to the soundboard and a main body (52, 52B) heavier than the vibration member, the excitation unit adapted to generate at least one of attraction force and repulsion force between the vibration member and the main body in response to a drive signal supplied thereto to vibrate the vibration member; a supporting unit (55, 55B) configured to support the main body so that less or no load of the main body is applied to the soundboard at least in a state in which the soundboard is not vibrated; a performance information generation unit adapted to generate performance information corresponding to an operation of the key; a signal generation unit adapted to generate an audio waveform signal based on the performance information, the generated audio waveform signal being supplied to the excitation unit as the drive signal to thereby vibrate the vibration member; and a controlling unit adapted to control the stopper in such a manner as to permit or not to permit the stopper to prevent the hammer from striking the sounding body when the vibration member is vibrated in response to the drive signal, wherein the main body (52, 52B) has a magnet, the vibration member has a voice coil which is arranged on a magnetic path formed by the magnet and to which the drive signal is input, and the vibration member and the main body (52, 52B) are separated from each other by space, wherein the supporting unit (55, 55B) supports the main body (52, 52B) such that the main body (52, 52B) is not in contact with the soundboard, and the supporting unit (55, 55B) is fixed to a supporting column of the keyboard musical instrument. a plurality of keys; a plurality of sounding bodies each provided in corresponding relation to each of the plurality of keys; a plurality of hammers each responsive to an operation of any one of the keys and adapted to strike the sounding body corresponding to the operated key; a stopper configured to be capable of preventing the hammer from striking the sounding body; a soundboard configured to be vibrated with vibration of the sounding body; an excitation unit including a vibration member connected to the soundboard and a main body (52, 52B) heavier than the vibration member, the excitation unit adapted to generate at least one of attraction force and repulsion force between the vibration member and the main body in response to a drive signal supplied thereto to vibrate the vibration member; a supporting unit (55, 55B) configured to support the main body so that less or no load of the main body is applied to the soundboard at least in a state in which the soundboard is not vibrated; a performance information generation unit adapted to generate performance information corresponding to an operation of the key; a signal generation unit adapted to generate an audio waveform signal based on the performance information, the generated audio waveform signal being supplied to the excitation unit as the drive signal to thereby vibrate the vibration member; and a controlling unit adapted to control the stopper in such a manner as to permit or not to permit the stopper to prevent the hammer from striking the sounding body when the vibration member is vibrated in response to the drive signal,