At home, in a pub, during a festival, a concert, in the street, etc.
It is music played as pre-programmed music
Starting from a music score, or from a live recording of a real musician playing on a special recording instrument, a transcription (we should say now: digitalization) is made of this score or of this recording on a cylinder by the means of pins, or by the means of holes in a paper roll or cardboard book. When the cylinder rotates, or when the paper roll or the cardboard book travels, the pins or the holes determines some actions which make the genuine automatic music instrument play instead of the original musician.
It is music played on genuine music instruments
Almost every music instrument has an automatic version: carillons, organs, pianos, violins, saxophones, etc. except those who need a mouthpiece (trumpets, horns), because it is not known how to make artificial lips.
These pre-programmed instruments which play mechanical music are the true ancestors of the computers