Calliope (music)
（重定向自Steam organ）
A calliope (see below for pronunciation) is a musical instrument that produces sound by sending a gas, originally steam or more recently compressed air, through large whistles—originally locomotive whistles.
A calliope is typically very loud. Even some small calliopes are audible for miles. There is no way to vary tone or loudness. The only expression possible is the timing and duration of the notes.