A tibia is a sort of

organ pipe An organ pipe is a sound-producing element of the pipe organ that resonates at a specific pitch when pressurized air (commonly referred to as ''wind'') is driven through it. Each pipe is tuned to a specific note of the musical scale. A set of ...

that is most characteristic of a

theatre organ A theatre organ (also known as a theater organ, or, especially in the United Kingdom, a cinema organ) is a type of pipe organ developed to accompany silent films, from the 1900s to the 1920s. Theatre organs have horseshoe-shaped arrangements o ...

. Tibia pipes are generally made of wood, stopped, from 16' (Occasionally 32') with the top octave pipes (above 1/2', or 6" made of metal, stopped, and pipes from 1/4', 3" made of metal and open. The mouth is cut very high, and the pipes have little harmonic development - the sound approaches that of a

sine wave A sine wave, sinusoidal wave, or just sinusoid is a curve, mathematical curve defined in terms of the ''sine'' trigonometric function, of which it is the graph of a function, graph. It is a type of continuous wave and also a Smoothness, smooth p ...

. There is usually a tremulant on the wind for Tibia pipes - the increase and decrease of wind pressure gives "life" to the sound.

See also