A musician who plays a carillon (a set of tuned bells); an expert performer on the carillon.
From French 'carillon' with French occupational suffix '-eur' (one who). This term entered English directly from French in the 19th century.
A carillonneur must know how to play dozens of bells at once while sitting at a keyboard that controls them—it's like being an organist, but instead of sound waves through pipes, you're controlling actual metal objects swinging in the air.
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