Amazing Grace on the Black Keys! ... I was told by a piano player that I only sing in the black keys. I have never been so proud to have had that statement made about ... For those of you who don’t know, a pentatonic scale is a musical scale or mode with five notes per octave, aka the black keys. Turns out, there a quite a few songs out there that can be played using only the black keys (hooray for lazy people)! For your convenience, we’ve joined together our very favorite picks below.