The Pentatonic Scale is anything but mysterious.

All music is based upon a major scale, which typically has seven notes:  G-A-B-C-D-E-F.

A very long time ago, someone discovered that five of these notes, when put together, always result in a pretty sound being produced. (Penta, from the Greek, meaning: five)

That simplicity is what makes for soothing, alway pleasant-sounding music. Forward, backward, this way or that—the pentatonic scale always sounds great.