Click on the keys and try to find which one is the highest.
This keyboard uses shepard tones to make an auditory illusion of infinite ascent or descent. I found online a sample synth sound and used Audacity to make it into a shepard scale. To make such an illusion, you make a sample, pitch-shift it into a chromatic scale. Then, add different tracks, and pitch-shift the original chromatic scale into various octaves. Finally, make the lowest octave fade in from silence and fade the highest octave to silence, to form the barber pole-like illusion, and then combine everything to finish the auditory illusion.
