The Tuning Fork

A steel fork put pitch in a pocket, turning it from an organ pipe into a portable standard.

Related

BaroquePitchConcert PitchOrgan

Before the tuning fork, pitch belonged to the room. The length of an organ pipe fixed the A of a church, and another city meant another standard. A steel fork turned this into an object you could carry in a pocket.

Time and place

London, around 1711. Tradition credits the invention to John Shore, a royal trumpeter, though the exact date is not documented. In the nineteenth century Scheibler built a tonometer from a set of forks in 1834, France fixed a standard pitch by decree in 1859, and a conference in Vienna confirmed it in 1885. The fork was the tool behind all of this work.

What happened

A tuning fork is two steel arms of equal length that sound an almost pure tone when struck, its frequency set by length and steel. It is less affected by temperature and humidity than a wind instrument, and it takes up no room, so it travels. Instrument makers used it to set the pitch of what they built, singers used it to find a note, ensembles used it to align their sections. Nineteenth-century makers added a sliding weight for fine adjustment, and pitch became something that could be measured, compared and written into tables.

What changed

Pitch turned from a local habit into a transportable standard. Instrument making acquired a reference that worked across cities, and organs, pianos and winds could be ordered to an agreed pitch in one contract. Standardisation had another face. Orchestral pitch climbed through the nineteenth century, singers complained that they could not reach the top, and conferences and decrees followed one another. The fork also moved part of listening into an object. Players still used their ears, but an argument could now produce a shared piece of evidence.

Listen for the turn

Begin with Handel's organ concerto, where pitch is built into the pipework and changes with the building, the local standard that existed before the fork. Then Purcell's trio sonata, strings and continuo finding a common pitch, the instrument in the room setting the reference. Finally Beethoven's Violin Concerto, strings tuning in fifths by ear, pitch passing from player to player. None of these recordings uses a fork; what you hear is pitch anchored to a fixed instrument.

Related

This turn belongs to Baroque; see Pitch, Concert Pitch and Organ.

Sources

• Grove Music Online, entry Pitch — tuning fork and conferences checked, not quoted
• Bruce Haynes, A History of Performing Pitch (Scarecrow Press) — fork history checked, not quoted

Used for fact-checking only; all prose is original.