w0rd. Solipsism.

Bobby McFerrin and the power of the pentatonic scale.

Bobby McFerrin demonstrates the power of the pentatonic scale, using audience participation, at the event "Notes & Neurons: In Search of the Common Chorus", from the 2009 World Science Festival, June 12, 2009.

What's going on here? How was the audience able to intuitively get it after only being shown two notes? What's special about the pentatonic scale that allows this to work around the world? After defining the first two notes, there are three scales that could follow. Why does the audience collectively, instantly, choose pentatonic? Interesting analysis here:

Now the audience is singing along in either the major scale or the major pentatonic scale, and we can't be sure which one it is, because the first three notes of each are identical.  So to break the uncertainty, Bobby defines a fourth note: the note below the base note, as being three half steps below the base note in pitch.  Now there isn't any more uncertainty.  Only the major pentatonic scale has such a half note progression (in the regular major scale, the note below the base note is only one half step below in pitch).  And the audience sings along, anticipating note after note both higher and lower than any Bobby had defined.

A few more awesome Bobby McFerrin videos are after the break.

(Via BoingBoing.)