A tibia is a sort of

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

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 of ...

. 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 sinusoid (symbol: ∿) is a periodic function, periodic wave whose waveform (shape) is the trigonometric function, trigonometric sine, sine function. In mechanics, as a linear motion over time, this is ''simple ...

. 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