Flats
A flat (b) does the opposite of a sharp. Placed immediately before any note, it lowers the pitch of that note by one semitone.
As with sharps, flats are cancelled by a bar line or by a natural sign.
Enharmonic Notes
The use of sharps and flats means that the same note can have two different names. For example, F# = Gb and G# = Ab. These are referred to as enharmonic notes. The following diagram outlines all of the notes in the first five frets of the mandolin (including both names for the enharmonic notes).
The following example demonstrates two octaves of the G chromatic scale. Notice that sharps are used when the scale ascends and flats are used as it descends. This is common practice when writing chromatic passages in music. As with any example containing new notes, it is important to name the notes out loud as you play through this scale.
Now play this typical Bluegrass example which makes use of sharps, flats and naturals.
