chiroplast
File:Drawing_of_piano_with_chiroplast.png
A chiroplast is an instrument to guide the hands and fingers of pupils in playing on the piano, invented and patented by Johann Bernhard Logier in 1814.Michael Kassler, A.F.C. Kollmann's Quarterly Musical Register (1812). An annotated edition with an introduction to his life and works, Ashgate Publishing, Ltd., 15 Dec 2008, {{ISBN|0-7546-6064-8}}, [https://books.google.com/books?id=rzP2qXHANQQC&dq=chiroplast&pg=PA123 pp. 123–31.] The instrument was a device that placed the wrist, thumb and fingers of a hand above five consecutive white keys of a keyboard, to overcome the difficulty of retaining their proper position by beginners.
The instrument was a key part of Logier's system of teaching, which was one of the first to call for the teaching of multiple students at once.{{DNB|wstitle=Eager, John|volume=16|last=Maitland|first=John Alexander Fuller|author-link=John Alexander Fuller Maitland|pages=311-312|short=1}} The use of the chiroplast caused a significant amount of criticism and controversy at the time, at least part of which was due to the heavy opposition to Logier's system by musicians fearing the loss of their students to centralized institutions teaching multiple students at once.
After being invented by Logier in 1814, it quickly became used by many.{{Cite book |last=Gerig |first=Reginald R. |url=https://archive.org/details/famouspianiststh0000geri |title=Famous pianists & their technique |date=1974 |publisher=Washington : R. B. Luce |others=Internet Archive |isbn=978-0-88331-066-3}} It was very popular in London in the 1810s and 1820s.{{Cite book |last1=Weitzmann |first1=Karl Friedrich |url=https://archive.org/details/historyofpianofo00weit/page/150/mode/2up |title=A history of pianoforte-playing and pianoforte-literature |last2=Lessmann |first2=Otto |date=1897 |publisher=New York : G. Shirmer |others=University of California Libraries |pages=150–151}} In 1822, Logier was invited by the Prussian government to Germany to set up a school instructing teachers on how to teach the use of the device in the country.
Description
The device consisted of a wooden framework screwed into place over the whole length of the keyboard.{{Cite journal |last=Rainbow |first=Bernarr |date=1990 |title=Johann Bernhard Logier and the Chiroplast Controversy |url=https://www.jstor.org/stable/966259 |journal=The Musical Times |volume=131 |issue=1766 |pages=193–196 |doi=10.2307/966259 |jstor=966259 |issn=0027-4666}} The user passed their wrists through two parallel wooden bars, which kept the hands at the correct distance from the keys. They then put their fingers into slots in two flat brass frames called "finger-guides" which could freely slide horizontally along a brass rod along the whole length of the keyboard. Each finger-guide had five divisions, through which each finger was placed.{{Cite Grove1900|wstitle= Chiroplast |volume= 1.11 | pages= 346-347 |last= Taylor |first= Franklin |author-link= Franklin Taylor |year=1900| short=1}} Each finger-guide was also attached to a stiff brass wire with a regulating screw, which kept the wrist in the proper position relative to the arm.{{Clarification needed|date=September 2024}}