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Pipe with different openings at node

Koenig Acoustical · Physics

This piece is a rectangular organ pipe, open at one end and exhibiting a mouth and round mouthpiece at the other. In the centre of this pipe a small section is cut from the body, into which a sliding slat has been inserted. Into this slat are cut round holes of various sizes, each labelled with a different note of the solfège scale. The slat can be slid across, changing the size of the opening. The last position, Ut3, has no hole.

Strips of velcro have been applied to the bottom surface.

Accession Number:

Alternative Name:

Primary Materials: Pipe: Pine; Lip, Slider: Mahogany


The top of the pipe near the spout is marked “85”, referring to Koenig’s 1873 catalogue. Near the mouth: “RUDOLPH KOENIG A PARIS”. On the sliding slat, marking the holes from smallest to largest: “UT3”, “RE3”, “MI3″, FA3”, “SOL3”. The back of the sliding slat is marked “85”.

Dimensions (cm): Height= 6.5, Width=28.4, Length= 62.5


This piece was intended to demonstrate how pressure changes at the nodal point of an organ pipe would alter its pitch.

According to David Pantalony’s “Altered Sensations” (New York: Springer, 2009): “There were many demonstrations that manipulated pressure changes at the nodal points. Changes in pressure alter pitch. Different sized holes at the node, therefore, produce different musical notes. Larger holes produce higher pitch.” (pg 241).


Good. Some chips and scratches are evident on the body of the pipe. The varnish is worn in places, and the sliding slat is somewhat loose.

Associated Instruments:

Manufacturer: Rudolph Koenig, Paris

Date of Manufacture: ca. 1878


These pipes are part of a collection of acoustic teaching apparatus purchased from Rudolph Koenig by University of Toronto professor of physics James Loudon. These pipes were part of Loudon’s initial 1878 purchase, and form part of a comprehensive selection of organ pipes “representing a… demonstration of every possible organ pipe effect.” (Pantalony, Altered Sensations. New York: Springer, 2009. Pg 119-122). These were likely used by students for investigations of acoustical properties at the university’s physics department teaching laboratory.

These pipes were collected from the Department of Physics, after a number had been used for some years as part of an interactive display.

Additional Information and References:

See also: “Altered Sensations: Rudolph Koenig’s Acoustical Workshop in Nineteenth Century Paris” by David Pantalony (New York: Springer, 2009) in the text’s Catalogue Raisonné under entry number #90, referring to the pipe’s entry in the 1889 catalogue (pg 241-2).

Historical Notes: