We can’t hear it with our ears, but the stars in the sky are performing a concert, one that never stops. The biggest stars make the lowest, deepest sounds, like tubas and double basses. Small stars have high-pitched voices, like celestial flutes. These virtuosos don’t just play one "note" at a time, either -- our own Sun has thousands of different sound waves bouncing around inside it at any given moment.
Understanding these stellar harmonies represents a revolution in astronomy. By "listening" for stellar sound waves with telescopes, scientists can figure out what stars are made of, how old they are, how big they are and how they contribute to the evolution of our Milky Way galaxy as a whole. The technique is called asteroseismology. Just as earthquakes (or Earth’s seismic waves) tell us about the inside of Earth, stellar waves -- resulting in vibrations or "star quakes" -- reveal the secret inner workings of stars.