Stringed instrument from Venus played by science fiction hero Captain Future between adventures. This may be the earliest appearance, in Calling Captain Future by Edmond Hamilton, first published in the Spring 1940 issue of Captain Future magazine.
In a different adventure, Captain Future also had to fight off Harpers.
She looked back at Captain Future. The big red-haired young man was lounging back in a space-chair, staring off into nothingness while his strong fingers plucked absently at his pet instrument, a twenty-string Venusian guitar.
Haunting music of a half-dozen different worlds, drifting snatches of subtle, unearthly melodies, came from the instrument. Yet Joan watched Captain Future’s brooding, handsome face and abstract gray eyes, knew that his mind was far from music.