The cornamuse is a double reed instrument from the Renaissance period. It is similar to the crumhorn because both have a windcap over the reed and a cylindrical shape. The only information about the cornamuse comes from a description and some comments by Michael Praetorius in Syntagma musicum II, published in 1619. Since Praetorius’s paragraph is the only clear description of the cornamuse and no examples or pictures from that time have been found, all attempts to rebuild the instrument are based on educated guesses.

In German, Praetorius wrote: "The cornamuse has a single tube, like the bassanelli, not a double one. It is closed at the bottom and has small holes on the sides through which the sound escapes. Its sound is similar to the crumhorn, but it is quieter, more gentle, and softer." This description shows that the cornamuse is different from other Renaissance instruments with double tubes, such as the sordun, kortholt, and curtal. Praetorius also compared the schryari to the cornamuse, saying they are nearly the same size and look.

The name "cornamuse" should not be confused with "cornemuse," which is the French word for bagpipes.