Young Brunette Girl At The Old Piano

Yet Bösendorfer, the Austrian manufacturer of extremely high quality pianos, constructs their rim from spruce, the very same wood that the soundboard is made from. Their idea is to concertedly involve the cabinet in the projection and coloration of sound. The loss of energy into the Bösendorfer case alters the instrument's tone, giving it perhaps less power but a complex and unusually resonant sound.
The finest hardwood rims are made by laminating thin (hence flexible) strips of hardwood, bending them to the desired shape immediately after the application of glue. This system was developed by Theodore Steinway in 1880. The thick wooden posts on the underside (grands) or back (uprights) of the piano stabilize the rim structure, and are made of softwood for stability. The requirement of structural strength, fulfilled by stout hardwood and thick metal, makes a piano heavy; even a small upright can weigh 136 kg (300 lb), and the Steinway concert grand (Model D) weighs 480 kg (990 lb). The largest piano built, the Fazioli F308, weighs 691 kg (1520 lb).
The pinblock, which holds the tuning pins in place, is another area of the piano where toughness is important. It is made of hardwood, (typically hard maple or beech), and is laminated for strength, stability and longevity. Piano strings (also called piano wire), which must endure years of extreme tension and hard blows, are made of high carbon steel. They are manufactured to vary as little as possible in diameter, since all deviations from uniformity introduce tonal distortion. The bass strings of a piano are made of a steel core wrapped with copper wire, to increase their mass whilst retaining flexibility. If all strings throughout the piano's compass were individual (monochord), the massive bass strings would overpower the upper ranges. Makers compensate for this with the use of double (bichord) strings in the tenor and triple (trichord) strings throughout the treble.
The plate, or metal frame, of a piano is usually made of cast iron. It is advantageous for the plate to be very massive. Since the strings vibrate from the plate at both ends, vibrations absorbed by the plate will result in energy loss to the desired (efficient) channel of sound transmission, namely the bridge and the soundboard. While some manufacturers now use cast steel in their plates, cast iron remains the preferred metal. Cast iron is easy to cast and machine, has flexibility sufficient for piano use, is tremendously resistant to deformation (unlike steel that can bend), and is especially tolerant of compressive forces. The casting of the plate is a delicate art, since the dimensions are crucial and the iron shrinks by about one percent during cooling.