barrel organ 
noun
A small pipe organ played by turning a handle, which rotates a cylinder studded with pegs that open the valves to produce a preset tune, formerly much used by street musicians.A barrel organ was in the street below playing ‘In the Sweet Bye and Bye,’ and one by one, the passengers took up the hymn....
- An alternative was the barrel organ, usually a small chamber organ for which the church could buy a selection of pinned barrels with the most popular hymn tunes of the day ready set.
- It is a stringed instrument, usually placed flat on the knee, and plucked somewhat like a guitar; it has been described as sounding something like a cross between a guitar and a barrel organ.