A pentatonic scale is a scale consisting of five (penta being the Latin word for five) notes. For example, between the fundamental note G and the G note one octave higher there are five notes in the G minor pentatonic scale. What makes playing a Native American style flute in a pentatonic scale so nice is that unlike a diatonic scale (seven note scale) all the notes and combinations of notes sound good together. There are no 'sour' notes to worry about when you play. If you play any five black keys on the piano in succession you're playing a pentatonic scale. If you have a keyboard around try it. There are five different pentatonic scales just like there are five black keys arranged in order. Depending on which of the five keys you start with you will have a different scale of five notes. For more information on pentatonic scales go to the Pentatonic Scales page
What is a pentatonic scale?