The black-key notes on a keyboard borrow the names of the white-key notes. A black key located to the right of a white key shares the same letter name as that white key, but with a "sharp" added.
The musical symbol for "sharp" is #. Therefore, the black key to the right of C is called "C sharp" ( C # ), and the black key to the right of D is called "D sharp" ( D# ), and so on, as shown in Figure 14:
We can also name the black-key notes in another way. A black key located to the left of a white key also shares the same letter name as that white key, but with a "flat" symbol added. As the name suggests, the black key to the left of D is "D flat" (bD), and the black key to the left of E is called "E flat" (bE) , and so on, as shown in Figure 15:
A letter name itself (for example "C") is generally understood to refer to the white key, but if you want to specifically indicate that the letter name refers to the white-key note, you can add a "natural" sign. The musical symbol for "natural" is the natural sign, so the full name of the white-key note C is "C natural".
