How do accordion bellows turn moving air into music?

An accordion player pulls and pushes a folded bellows while pressing keys or buttons. The bellows supplies airflow, but the keys choose where that air can go. Together they let the instrument sustain several notes while the player shapes the phrase.

Expanding the bellows makes pressure inside lower than the surrounding air, drawing air inward through open passages. Compressing it pushes air outward. A pressed key opens a valve leading to selected reeds: thin metal tongues fixed at one end over closely fitting openings.

Airflow interacts with a reed so that its free end vibrates through the opening. The reed repeatedly changes the air passage, producing pressure fluctuations that become sound. Its dimensions and stiffness help set the note. The player’s arm supplies energy through the bellows rather than directly plucking the metal tongue.

Reed arrangements accommodate the two airflow directions. Many accordions give the same note on a chosen key when pushing or pulling; other designs give different notes. That difference is part of the instrument’s design, not a mistake in the player’s movement.

Opening the air button provides a route for air without intentionally sounding the playing reeds. It reveals the division of jobs: moving air is necessary, but the chosen route determines whether and which notes sound. The accordion combines a hand-operated air source, selectable valves and vibrating metal tongues in one portable instrument.