A Music Roll
is used to operate a Mechanical organ
, electronic carillon
, or Orchestrion
the music to be played. Originally made of paper, modern rolls are sometimes made of thin plastic or PET film
The music is stored by means of perforations. The mechanism of the instrument reads these, as the roll unwinds, using a pneumatic sensing device called a tracker bar, and the mechanism subsequently plays the instrument.
A piano roll is a specific type of music roll, and is designed to operate a player piano.