The use of sharps and flats means that the same note can have two different names. For example, F# is the same as Gb and G# is also Ab. These are referred to as enharmonic notes. The following diagram outlines all of the notes in the first position on the guitar (including both names for the enharmonic notes). The first position consists of the open string notes and the notes on the first four frets.
Here is an exercise to improve your knowledge of flats. Identify the following notes and find each on your guitar.
The following example demonstrates two octaves of the E chromatic scale. Notice that sharps are used as the scale ascends and flats 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 practice this scale.
Now play this example which makes use of sharps, flats and naturals.
Hall of the Mountain King contains many chromatic notes. Remember that the sharp sign (or flat sign) affects all notes of that name within the bar in which it appears. For example, in bars 3 and 19 the first note of the bar is Bb. The flat sign written next to this note also affects the third note in the bar. Similarly, in bars 10, 12, 14 and 25 there is a sharp written before the first note of the bar. This sharp affects all other notes of the same name within these bars.