The Human brain seeks patterns in everything. This is why we see dinosaurs in clouds, faces everywhere, and even religious icons on irregularly burnt pieces of bread. Our minds seek patterns in color, number, sound, figures, and even events. At the 2009 World Science Festival, Bobby McFerrin demonstrates exactly this. He uses an unsuspecting audience to prove that the pattern seeking brain can produce the Pentatonic scale, which is defined as a scale of five notes per octave. Enjoy.
Bobby McFerrin Demonstrates The Pattern Seeking Brain