Mandolin
A mandolin was a small, stringed guitar-like instrument.

When Q abducted the senior staff of the  in 2367 and displaced them into a Sherwood Forest-like environment, Geordi La Forge played the role of Alan-a-Dale.

Completely in character, he tried to play the mandolin, very much to the dislike of Worf, who smashed the instrument into bits and pieces, although he did apologize. ()

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Earth musical instruments