Sharps (#) and Flats (b)
Although there are only seven letter names used in music, there are actually twelve different notes used in music. The extra notes fall in between some of the letter names. These notes are indicated by the use of sharps and flats.
A sharp is indicated by the symbol # and means that the pitch is raised by a semitone. For example, the note C sharp (C# ) is higher than C and falls halfway between the notes C and D. A flat is indicated by the symbol b and means that the pitch is lowered by a semitone.
For example, the note Db is lower than D and falls halfway between D and C. This means that the notes C# and Db are exactly the same. This may seem confusing but is easy to understand if you look at the piano keyboard shown in the following diagram.
The white notes are all the natural notes (A B C D E F G) and the black notes are the sharps and flats. D# is the same as Eb, F# is the same as Gb, etc. Sometimes one is used and sometimes the other, depending on the musical situation and the key the music is written in. Keys are discussed later in this lesson.
