String instruments: When a string is plucked, bowed, or strummed, it vibrates. This vibration causes the surrounding air to vibrate, creating sound waves. The pitch of the sound depends on the string's tension, length, and thickness.
Wind instruments: When air is blown across an opening in a wind instrument, it creates a turbulent flow of air. This turbulence causes the air inside the instrument to vibrate, producing sound waves. The pitch of the sound depends on the length of the tube and the size and shape of the opening.
Percussion instruments: When an object is struck or scraped, it vibrates. These vibrations cause the surrounding air to vibrate, creating sound waves. The pitch of the sound depends on the size, shape, and material of the object being struck.
Electronic instruments: Electronic instruments use electronic circuits to generate sound waves. These circuits can create a wide variety of sounds, from simple beeps to complex sounds that mimic traditional acoustic instruments.