An orchestrion is a generic name for a machine that plays music and is designed to sound like an orchestra

Orchestra

An orchestra is a sizable instrumental ensemble that contains sections of string, brass, woodwind, and percussion instruments. The term orchestra derives from the Greek ορχήστρα, the name for the area in front of an ancient Greek stage reserved for the Greek chorus...

 or band. Orchestrions may be operated by means of a large pinned cylinder

Barrel organ

A barrel organ is a mechanical musical instrument consisting of bellows and one or more ranks of pipes housed in a case, usually of wood, and often highly decorated...

 or by a music roll

Music roll

A music roll is a storage medium used to operate a mechanical musical instrument. They are used for the player piano, mechanical organ, electronic carillon and various types of orchestrion. The vast majority of music rolls are made of paper...

 and less commonly book music

Book music

Book Music is a medium for storing the music played on mechanical organs, mainly of European manufacture. Book music is made from thick cardboard, containing perforated holes representing the musical notes to be played, with the book folded zig-zag style...

. The sound is usually produced by pipes, though they will be voiced differently to those found in a pipe organ

Pipe organ

The pipe organ is a musical instrument that produces sound by driving pressurized air through pipes selected via a keyboard. Because each organ pipe produces a single pitch, the pipes are provided in sets called ranks, each of which has a common timbre and volume throughout the keyboard compass...

, as well as percussion instruments. Many orchestrions contain a piano as well.
The first known automatic playing orchestrion was the panharmonicon

Panharmonicon

The Panharmonicon was a musical instrument invented in 1805 by Johann Nepomuk Mälzel, a contemporary and friend of Beethoven. Beethoven apparently composed his piece "Wellington's Victory" to be played on this behemoth mechanical orchestral organ to commemorate Arthur Wellesley's victory over the...

 a musical instrument invented in 1805 by Johann Nepomuk Mälzel

Johann Nepomuk Mälzel

Johann Nepomuk Maelzel [or Mälzel] was an inventor, engineer, and showman, best known for manufacturing a metronome and several music automatons, and displaying a fraudulent chess machine.-Life and work:...

.