A grand piano includes a pedal mechanism constituted by a lyre block attached to the lower surface of a piano case, pedal posts hung from the lyre block, a lyre box engaged with the pedal posts, pedals rotatably supported by the lyre box and pedal rods connected between the pedals and damper mechanism/keyboard accommodated in the piano case, wherein the lyre box is movable along the pedal posts, and a coupler is provided between the lyre box and the pedal posts so as to maintain the pedals at a position suitable for a pianist, whereby the pianist can adjust the pedals to the suitable position before fingering on the keyboard.