When singing notes in cumulative order of black and white keys on the piano, you are playing a chromatic scale. Keys raised by half step use sharp (), while flat () lowers the pitch by half step.
A series of 13 consecutive half step keys in ascending or descending order makes up a chromatic scale.
(Ascending Order)
(Descending Order)
Sharp is used in ascending order while Flat is applied in descending order of the Chromatic Scale.