Playing the Black Piano Keys, Is That Correct?

Early instruments, or early music, you didn't have to necessarily be in tune with lots of other things. So if you ant that basic scale, you've got the white notes. If you start at note c, you can play the full key of c major by only playing the white piano keys. However, because of the way a piano set up, if you want to play the key of,. say, b major or d major, you would just start the note of bord. But then you'd also have to play some of the black piano keys, right? Yes.