curtal, Renaissance-era musical instrument and predecessor of the bassoon, with a double-back bore cut from a single piece of wood and built in sizes from treble to double bass (sometimes called the double curtal in England and the Choristfagott in Germany). The curtal was developed in the 16th century, probably in Italy, to be used with choirs as a bass that would be less clamorous than the brasses of the time.
Both open and stopped curtals were produced, and some had perforated lids to soften the sound. “Curtal” also referred in England c. 1700 to the true bassoon.