The early bladder pipe is in a family of the early medieval "chorus" instruments, a word which in medieval Latin was frequently used also for the bagpipe. In the earliest illustrated forms of bladder pipe, such as the well-known example of the 13th century reproduced by Martin Gerbert from a manuscript at Sankt Blasien Abbey in the Black Forest, the bladder is unusually large, and the chanter (or melody pipe) has, instead of a bell, the carved head of an animal. At first the chanter was a straight conical tube terminating in a bell, as in the bagpipe. The later instruments have a pipe of larger calibre more or less curved and bent back as in the letter "J" as the crumhorn, tournebout, and cromorne. This curvature, coming from the shape of an animal horn, suggests the early crumhorn's development from a bladder pipe. One famous illustration of these bladder pipes appears in the 13th-century Spanish manuscript, known as the "Cantigas de Santa Maria" in the library of El Escorial in Madrid, together with a bladder pipe having two pipes, a chanter and a drone side by side. Another Platerspiel David is illustrated by Sebastian Virdung (1511).