> Both C#m and Db can be played on piano using only the black keys (skipping the 3rd note of the scale)
For the major scale, there are 7 notes in the scale and only 5 black keys; you also need to skip ti, the 7th note.
For the minor scale ("C#m"), it's worse; only four of the five black keys are part of that scale.
And I would have thought that something intended to be played only on the black keys would be described as using a pentatonic scale anyway?
