A sharp raises a note by: a whole step a half step two whole steps, one and 1/2 steps
A sharp raises a note by a half step.
In music theory, a half step (also known as a semitone) is the smallest interval between two adjacent notes in Western music. So when you raise a note by a sharp, you move it up by one half step.
For example, if you have the note C and you raise it by a sharp, you get C# (C sharp). Similarly, if you have the note A and you raise it by a sharp, you get A# (A sharp).
It's important to note that some notes have enharmonic equivalents, which means they can be spelled differently but they sound the same. For example, C# and Db (D flat) are enharmonic equivalents because they represent the same pitch on a piano keyboard, even though they have different letter names.
Now, when it comes to intervals, a whole step is made up of two half steps. So if you raise a note by two half steps, you are raising it by a whole step.