Keyboard: The Orchestra: A User's Manual — Andrew Hugill
“The aim of The Orchestra: A User's Manual is to provide information about the orchestra, orchestration, composition and instruments, for the benefit of anybody with an interest in the subject.”
Piano: Encyclopedia Britannica
“piano, also called pianoforte, French pianoor pianoforte, German Klavier, a keyboard musical instrument having wire strings that sound when struck by felt-covered hammers operated from a keyboard. The standard modern piano contains 88 keys and has a compass of seven full octaves plus a few keys.”
Piano: Instrument Guide — Yamaha
“The piano is a keyboard instrument that produces sound by striking strings with hammers, characterized by its large range and ability to play chords freely. It is a musical instrument that has broad appeal.”
Piano: Instrument Studies for Eyes and Ears — Jacobs School of Music
Instrument Studies for Eyes and Ears, by Don Freund, site designed by Reid Merzbacher
Piano: The Orchestra Up Close — Orchestre Métropolitain
“There are two kinds of instruments in the string family, the first are the “bowed” instruments, like the violin. The second are the plucked, or hammered instruments, like the piano, whose strings are struck by a small hammer which moves when a player pushes down a key.”