From Academic Kids
The crumhorn is a musical instrument of the woodwind family. It was popular in the Renaissance period. In the 20th century, there was a revival of interest in Early Music and people started to play crumhorns again.
The name derives from the German krumhorn (or krummhorn or krumphorn) meaning bent horn. This relates to the old English crump meaning curve, surviving in modern English in 'crumpled' and 'crumpet' (a curved cake).
The crumhorn is a capped reed instrument. Its construction is similar to that of the chanter of a bagpipes. A double reed is mounted inside a chamber at one end of a long pipe. Blowing into the chamber produces a musical note. The pitch of the note can be varied by opening or closing finger holes along the length of the pipe. One unusual feature of the crumhorn is its shape; the end is bent upwards in a curve, so that the instrument resembles a banana, or more prosaically, the letter J.
Crumhorns sound nothing like a trumpet, something like an oboe, and nothing like a duck. They make a strong buzzing sound. They have a limited range, usually an octave and one note; while it is theoretically possible to get the reed to overblow a twelvth above the fundamental note, this is practically extremely difficult, since the reed is not held in the mouth, so in practice all playing is confined to the fundamental series. Some larger instruments have their range extended downwards by means of additional holes and sliders or by dropping the pressure. Because of the limited range, music for crumhorns is usually played by a group of instruments of different sizes and hence at different pitches. Such a group is known as a consort of crumhorns.
A source of more useful information on this musical instrument can be found on the Crumhorn Home Page at http://www.iinet.net.au/~nickl/crumhorn.html