How do wind instruments use vibrating air to produce sound?

Wind instruments, classified as aerophones in the Sachs-Hornbostel system, produce sound by using air as the primary vibrating medium. The process involves setting an enclosed column of air into motion through a sound-generating device, which creates regular pulsations that form sound waves.12

The method of initiating this vibration varies by instrument type:

• Edge instruments (flutes): An airstream directed against a sharp edge—either by the player's lips or through a duct—sets the air column within the tube into pulsation.1
• Reed instruments: Air pressure from the performer sets a single or double reed into motion, which in turn vibrates the air column.31
• Trumpet-type instruments (brasses): The performer’s compressed lips vibrate against a mouthpiece, creating air pressure eddies that activate the enclosed air column.31

Once the air is in motion, the tube acts as a resonator, where waves reflect back to create standing waves with specific nodes and antinodes. By changing the effective length of the tube—using fingers, keys, valves, or slides—the player alters the pitch.23