Leo Fender put a spring-powered lever to control the pitch of guitar strings on a Stratocaster. You might know this as a "Whammy Bar" but originally, he called it a Tremolo Bar. The problem with this name is that tremolo is a completely different thing. It refers to volume modulation, not pitch!
Sanjay SrivastavaWhat is an extremely nerdy/obscure/specific thing you hate with a white-hot wrath?