Calliope

A calliope (see below for pronunciation) is an American and Canadian 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. Musically, the only expression possible is the pitch, rhythm, and duration of the notes.
The steam calliope is also known as a steam organ (... plus