Here's how to play a Major Pentatonic Scale. The Pentatonic Scale has five notes. It's comprised of the first three notes of a major scale,and then the fifth and sixth note on the major scale. In the key of C, we start at C and we play a C, D, E, G, A, which brings back to C. I'll demonstrate a two octave C pentatonic scale for you. That's how to play a Major Pentatonic Scale on the bass guitar.