mutation stop

pipe organ

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Last updated

July 1, 2026

Quick Summary

A "mutation stop" on a pipe organ is a mechanism that produces pitches other than those indicated by the notes played or their octaves, such as a fifth or a twelfth. These stops are used in combination with unison pipes to add a distinct quality to the organ's sound. The term "mutation" in this context refers to these added intervals, not to genetic mutations.123

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keyboard instrument
Organ stops
Such stops are known as mutation stops, as opposed to the mixtures, or chorus stops. Their use is essential for the historically (and therefore artistically) correct performance of organ music written before 1800 and of much modern music as well. After a period of disuse throughout the 19th century, they…
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Such stops are known as mutation stops, as opposed to the mixtures, or chorus stops. Their use is essential for the historically (and therefore artistically) correct performance of organ music written before 1800 and of much modern music as well. After a period of disuse throughout the 19th century, they…
Read More

stop
Mutation stops consist of pipes sounding higher (e.g., by five notes) than the other pipes, rather than in unison with them. Used in combination with unison pipes they add an incisive quality to the sound. Mixture stops consist of two or more ranks of pipes,…
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Mutation stops consist of pipes sounding higher (e.g., by five notes) than the other pipes, rather than in unison with them. Used in combination with unison pipes they add an incisive quality to the sound. Mixture stops consist of two or more ranks of pipes,…
Read More