Before looking at how the pianola developed further, let’s get back to that hurdy-gurdy.
By turning the wheel of the hurdy-gurdy, the player ensures that the wheel rasps against the strings of the instrument, causing a smooth, constant vibration of the string. This is easier to operate than the violin or other bowed instruments, which require the player’s arm to be carefully positioned - and moved - to produce a good tone. Unlike the bowing arm of a violinist, which has to change direction into ‘downbows’ and ‘upbows’, the bowing wheel of the hurdy-gurdy can continue as long as the player keeps on turning the wheel.
But… how would a machine play SEVERAL violins - simultaneously?
The answer is here: the phonoliszt violina, designed by Hupfeld! For this instrument, a type of orchestrion (a large wheel) rotates around all the violins, while the pianola provides the accompaniment.
You can see another version of this instrument being played here, giving an arrangement of Chopin’s Nocturne No.9: