Which of these sound techniques existed before the post-World War II era?

Question

Quizplus · Accepted Answer

Plucking stringed instruments instead of bowing them has been a common technique in music for centuries and predates the post-World War II era. The other techniques listed (multiphonics for woodwind players, use of "nonmusical" noises, and electronically produced sound) all emerged or became more prominent in the post-World War II era with new technology and experimentation.

Which of These Sound Techniques Existed Before the Post-World War