The French expression for "organ grinder" is "joueur d'orgue de
Barbarie" (barrel organ player).

You can also find today "tourneur d'orgue" (one who turns an organ)
but it is not so correct and pleasant.

When you read in an old book "joueur d'orgue de Barbarie" it means
that it was a poor man, often a disabled ex-serviceman (with a woman
or a family), playing from place to place a little barrel organ,
sometimes with a dog or a little monkey.  Sometimes he can also
sing the new songs of the day or he can also sell little things
like ribbons, needles, religious pictures or unauthorized books!
He was also very important for the news!

The phrase "de Barbarie" has some explanations.  Perhaps it comes
from the name Barbieri, a very old organ maker in Italy, or from the
word Barbarie, which means "from foreign countries" in Latin and later
in French.  In the XIXth century many people traveled through different
countries (merchants, workers, stallkeepers and also grinders...)

Please if you have another questions, I'll try to help you.

Best regards from France,
Françoise Dussour