Patent ID: 7858858

Claim:
An upright piano that is played while switching a playing mode between a first playing mode in which acoustic playing is performed by striking a string using a hammer which pivotally moves in accordance with depression of a key, and a second playing mode in which playing is performed while detecting a rotational position of the hammer, comprising: a sensor disposed at a location close to a turning path of the hammer, for detecting a rotational position of the hammer in the second playing mode; a hammer rest rail which is pivotally movable and with which the hammer is in contact in a key-off state of the key; a soft pedal which is stepped on so as to give a soft pedal effect; a pedal rod having a lower end thereof connected to said soft pedal, for being moved upward as said soft pedal is stepped on, to thereby push up said hammer rest rail to cause said hammer rest rail to pivotally move toward the string; a spring interposed between said pedal rod and said hammer rest rail; a stopper which is disposed above a top of the hammer rest rail and which is engageable with the hammer rest rail, wherein the stopper is movable between a permitting position in which said stopper is retreated from said hammer rest rail to permit motion of said hammer rest rail caused by pushing-up of said pedal rod and a blocking position in which said stopper is in abutment with said hammer rest rail to prevent the motion of said hammer rest rail caused by the pushing-up of said pedal rod so that the position of the hammer in the key-off state of the key is held in the same position as it is in the non-stepped-on state of the soft pedal; and a stopper drive mechanism that drives said stopper to the permitting position in the first playing mode and to the blocking position in the second playing mode.