organ grinder

Meanings

1. The player of a barrel organ.
2. The person who is in charge, rather than a lackey or representative; the person truly responsible for another's actions.

Etymology

From the repetitive grinding involved in playing a barrel organ. In figurative senses, from the common 19th-century practice of training monkeys to dance to an organ grinder's music in order to perform on the street and solicit donations and spare change.