The Dulcian (Curtal)
The dulcian is one of the most important instrumental innovations of the Renaissance. It is known by many names, either from curtus, the Latin word for short, or dulce for sweet. It is the first major instrument to have a double bore (think of a pipe bent in two, like a horseshoe) and thus had a sound twice as low as its outside length.
It is unsure where exactly the dulcian was invented, though some sources suggest Italy. The instrument was created primarily to serve the need for a less unwieldy orchestral bass. Originally, it was produced in consorts ranging from soprano to bass. It is the direct ancestor of the modern bassoon.
Sound clips, pictures, and information can be found on http://www.hansmons.com/dulcians/#overview.
----------
Works Consulted
"Dulcians" {http://www.hansmons.com/dulcians/#overview}
"Dulcian (Curtal)" {http://www.s-hamilton.k12.ia.us/antiqua/dulcian.htm}