Partial view of the insides of a grand piano
The wooden plank with holes in the right-hand part of the picture is the wrestplank without strings and tuning pins. When the instrument is strung, the tuning pins around which the strings are wound, fit tightly into the bore holes, visible on the left.
Tuning pins with attached strings. The pinblock, in which the pins are inserted is covered by the iron frame.
The inside of a partly-strung grand piano.
The light-coloured surface under the iron frame and strings is the spruce soundboard. The blue sections in the middle are the bridges which are glued to the soundboard and are responsible for transferring the string vibrations to the wood.
Here is an ivory keyboard that has yellowed. The unsightly discolouration can be removed by a technician.