Although most often associated with Scotland and the so-called Highland Pipes, these instruments were known from many regions over a long period of time. There are bagpipes from the British Isles, as well as France, Spain, Italy, and even Eastern Europe. They come in all sizes and shapes, but the one common factor is that the note (or notes) are produced by reeds, usually sounded by arm pressure on a flexible bag of some sort (traditionally sheep or goatskin). As the bag is pumped, air is forced across the reeds, producing a musical pitch. All bagpipes have at least one melody pipe, which is called a chanter, while additional tuned pipes will produce a drone, or more likely a set of drones. The earliest records of a bagpipe being played are lost in antiquity, although scholars point to a treatise written by John Cotto in the 12th century where he mentions a “musa,” which historians say is without doubt a bagpipe. By the 13th century, references to such instruments became much more commonplace. The Uillean Pipe (also known as the Irish Pipe) is considered the most modern and most complex, having been developed sometime during the 18th century.