A calliope 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 piano roll is a music storage medium used to operate a player piano, piano player or reproducing piano. Piano rolls, like other music rolls, are continuous rolls of paper with holes punched into them. These perforations represent note control data. The roll moves over a reading system known as a tracker bar; the playing cycle for each musical note is triggered when a perforation crosses the bar.