Metal Tuning Key
The harp's tuning key is one of the most commonly used accessories.
There are two types of harp tuning keys. One has a wooden handle and a metal "shaft":
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Metal tuning key
The other is completely rubber-covered:
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Rubber tuning key
Nowadays most harpists have a rubber-covered tuning key for tuning their instruments. However, many have a metal one specially to use for effects. As an alternative to a metal tuning key, a screwdriver with a relatively thick "shaft", a thick percussion triangle beater, or a cylindrical metal object can be used.
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Triangle beater, guitar slide.