To enjoy affluent and powerful playing sound by more efficiently utilizing the sound waves emitted from the sound emitting sections of sound generating bodies.

A musical instrument main body 1 is provided with a keyboard section 10 made of a plurality of keys 11 and loudspeakers 35 which are the sound generating bodies arranged behind the keyboard section 10. A top surface plate to cover the top section of the musical instrument main body 1 and a top surface cover section to cover an operating panel or the like are arranged behind the keyboard section 10. Tone escape sections are provided at the right and left positions separated in the key arrangement direction of the musical instrument main body 1 in the operating panel. A decorative plate 2 is raised on top of the top surface plate behind the tone escape sections. The width of the decorative plate 2 is made equal to or wider than the total width of the keyboard section 10 in the key arrangement direction and the height of the plate 2 is made equal to or greater than the length of the keys 11 in its longitudinal directions.