The chalumeau (English: /ˈʃæləmoʊ/; French: [ʃa.ly.mo]; plural chalumeaux) is a single-reed woodwind instrument of the late baroque and early classical eras.

It has a cylindrical bore with eight tone holes (seven in front and one in back for the thumb) and a broad mouthpiece with a single heteroglot reed (i.e. separate, not a continuous part of the instrument's body) made of cane.

[3] Several French dictionaries in the sixteenth century use the word to refer to various types of simple, idioglot reed-pipes all with tone holes.

[3] Around this time, well-known Nuremberg instrument maker Johann Christoph (J.C.) Denner made improvements to the chalumeau, eventually developing it into the Baroque clarinet.

Denner also reduced the size of the hole and inserted a small tube to facilitate overblowing, greatly increasing the range of the instrument to nearly three octaves.

[3] The limited range and modest strength of sound compared with the clarinet made the chalumeau increasingly impractical.

Graupner wrote extensively for all sizes of chalumeaux and featured the instrument, often in groups of two or three, in numerous Ouverture-Suites, Concertos, Church Cantatas and Trio Sonatas.

Of the original instruments, most are made of boxwood and all feature two keys placed opposite each other to be played by the thumb and first finger of the left hand.

[4] The surviving chalumeaux were made between the beginning of the eighteenth century and about 1760 by five known instrument makers including J.C. Denner, W. Kress, Liebau, Klenig, and Muller.

[3] Present day makers of replica chalumeaux include Peter van der Poel, Andreas Schöni, R. Tutz, François Masson, and Guntram Wolf.

[6] Similar single-reed folk instruments with single, cylindrical tubes are found in many Arabic and European cultures throughout history.