|"Is this all real? Or has this been happening inside my head?"
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Used as an instrument
A harp is a stringed musical instrument with the plane of its strings positioned perpendicular to the soundboard. Harps can be enchanted to be played without assistance.
During the 1991–1992 school year at Hogwarts, a harp was used by Quirinus Quirrell to prevent the three-headed dog Fluffy from waking up while Quirrell attempted to steal the Philosopher's Stone for Lord Voldemort.