Pulsars are known to rotate at very predictable frequencies. If a beep or short tone is assigned to each rotation, the spin of the star can be 'sonified'. Pulsars spin anywhere from a few fractions of times per second to over 600 per second. 600 cycles is audible in the human range of hearing. However if the spin were anything over 20,000 times per second, it would cease to be audible, naturally, to the human ear. What celestial objects do we know of that spin, orbit or otherwise vibrate naturally at a rate between 20 times per second and 20,000?