The Collaborative International Dictionary of English v.0.48:

Pandean pipes \Pan*de"an pipes\, n. pl.,
   A primitive wind instrument, consisting of a series of short
   hollow reeds or pipes, graduated in length by the musical
   scale, and fastened together side by side; a syrinx; a mouth
   organ; -- said to have been invented by the god Pan. Called
   also pipes of Pan, Pan's pipes and Panpipes.
   [1913 Webster]