The back check is identical with that of the square.

The dampers are the same in their working principles as those of the
square, but are generally different in construction; yet, some squares
have the same arrangement of dampers as those shown in the cut of the
grand action.

The soft pedal of the grand shifts the entire action to the right so
that the hammers strike only two and in some cases only one of the
strings.

The student should study the three types of actions from the actions
themselves, if possible.

[Illustration: ACTION OF THE GRAND PIANO.]

ACTION OF THE GRAND PIANO.

1. Indicates the felt, cloth or leather, upon which the various
parts of the action rest, or fall noiselessly.

2. Key.

3. Bottom; sometimes called Key Rocker.

4. Extension; split at lower end to receive center pin in Bottom.

5. Wippen Support.

6. Jack.