Tracing the roots of the piano to the very beginning of consciousness, when man first became aware of sound.
3rd Century BCE, Hydraulus
The concept of a keyboard most likely originated in the 3rd century B.C.E. with the earliest incarnation of the organ, the hydraulus. To manipulate the sound, players manipulated hinged or pivoted levers, pressing downward to open up the passage of air to various pipes.
By the Middle Ages, the mechanical action was typically reversed, in the form of a slider or turn-key pulled outward to sound notes. Not until the portable organ, and then the organistrum, would the concept evolve into a formal keyboard.