This video shows that humans have a universal appreciation and understanding of music. In this live demonstration, musician Bobby McFerrin uses audience participation to show that, when given two notes, the other notes of the pentatonic scale can be reliably elicited. That everyone automatically understands this scale, regardless of where, when and what qualifications s/he has, from a musical genius to a child, this is a natural phenomenon. Whether the pentatonic or ionian scales, the consensus on any scale is interesting.

The point is to demonstrate that people naturally know the pentatonic scale. McFerrin starts by singing the first two notes for the audience, leaving the third note undecided. If the next note goes up a half step, the song is Db minor. If it goes up a full step, the song is Db major. Without thinking, the entire audience automatically chose to go up a full step and turn the song into Db major, sticking with the pentatonic scale.

This was from the event, "Notes & Neurons: In Search of the Common Chorus", from the 2009 World Science Festival, held on 12 June 2009.