There is a big cast-iron frame inside, mounted on a sound board, over which the strings are tensioned to phemoninal poundage. Only cast-iron can take the strain. Add to that the key and hammer...
Very little. The "grand" in grand piano comes from the Italian word "grande" meaning large or big. the only real difference is the size of the piano, and the grand piano is able to play at a higher...
A concert grand is usually between 8 and 9 foot long. A studio grand is usually between 5 foot 5 inches and 7 foot long.
A baby grand is usually 4 to 4 foot 6 inches long
All grand pianos are...