A wall panel-ceiling engagement device is designed to couple a wall panel to a ceiling. The engagement device, when engaged with the ceiling, holds the wall panel stationary without any fasteners, braces or other securing members that penetrate into the ceiling. The engagement device includes a pair of wall extensions secured to opposite sides of the wall panel and that contain a sound and/or attenuating material, such as a foam material, therebetween. Corner braces are used to join adjacent wall-panels to one another. The corner braces also function to allow the wall panels to sway as a collective and connected unit during seismic events.