OPERA, n.
A play representing life in another world, whose inhabitants have no speech but song, no motions but gestures and no postures but attitudes. All acting is simulation, and the word _simulation_ is from _simia_, an ape; but in opera the actor takes for his model _Simia audibilis_ (or _Pithecanthropos stentor_)--the ape that howls.
The actor apes a man--at least in shape; The opera performer apes and ape.
--Ambrose Bierce - The Devil's Dictionary