The story
Probably onomatopoeic in imitation of the sound produced by the stringed instrument. Compare obsolete hirdy-girdy (“an uproar; noise”). Attested from the 1740s.
Etymology from Wiktionary, CC BY-SA 4.0.
hurdy-gurdy
Today it means: A stringed instrument that produces a droning sound by turning a handle that connects to a wheel that rubs against a rosined string, with a keyboard also used to alter the pitch of the string. Full definition →