A scale can be defined as a series of notes in alphabetical order, going from any one note to its octave. Each scale is based upon a set pattern. In Lesson Ten you were introduced to the notes of the musical alphabet set out as such:
In this scale, B to C and E to F were said to be a semitone apart, with all other notes being a tone apart. In the chromatic scale, however, all notes are separated by a semitone, giving the following pattern:
The new notes that the chromatic scale introduces are called sharps and flats.
indicates a sharp, which raises the pitch of a note by one semitone. (see fretboard diagram)
indicates a flat, which lowers the pitch of a note by one semitone.
Thus it is possible for the same notes to have two different names. (e.g., F sharp has the same position on the fretboard as G flat). Here is a representation of the chromatic scale on the fretboard.