Eight foot pitch


The pipe organ is a musical instrument commonly used in churches or cathedrals that produces sound by driving pressurized air (called wind) through pipes selected via a keyboard. Because each organ pipe produces a single pitch, the pipes are provided in sets called ranks, each of which has a common timbre and volume throughout the keyboard compass. Most organs have multiple ranks of pipes of differing timbre, pitch and loudness that the player can employ singly or in combination through the use of controls called stops. An organ pipe, or a harpsichord string, designated as eight-foot pitch is sounded at standard, ordinary pitch. ( Pitch is a perceptual property that allows the ordering of sounds on a frequency-related scale). For example, the A above middle C in eight-foot pitch would be sounded at 440 Hz (or at some similar value, depending on how concert pitch was set at the time and place the organ or harpsichord was made). The particular length “eight feet” is based on the approximate length of an organ pipe sounding the pitch two octaves below middle C, the bottom note on an organ keyboard. Its fundamental frequency can be calculated (approximately) by the speed of sound and the length of the pipe.

Related formulas


fThe fundamental frequency (hz)
vThe speed of sound (the speed of sound at sea level, with temperature 70 degrees Fahrenheit is 1130 feet per second (feet/s)
lThe length of the pipe (feet)