Identify the key the music is written in (that is, the key signature). On the left side of the first line before the clef is a set of symbols. The symbols will be either a number sign, which in music is a sharp (A#). Or it will be an italic b, which is a flat (A?). Knowledge of key signatures and the order of sharps and flats is necessary. For instance one sharp, which will always be F#, is the key of G major. One flat, which will always be B?, is the key of F major.
Scan the staff for unnecessary accidentals. Unnecessary accidentals are sharps and flats that remind you through a piece of music that particular notes are sharp or flat. They are always within parenthesis to show that they do not alter the key. These are unnecessary because of the key signature and are usually written in beginner music. A note that is sharp or flat in the key signature will continue to be so unless it is changed by an accidental.
Identify accidentals. Normal accidentals alter certain notes from the original key signature to change the quality of harmonies. A piece of music written in the key of C major has no sharps or flats. However, if the F has a sharp after it, the pitch is raised one half step from F to F#. The resulting chord is called a raised fifth. If in the same key (C major) the E has a flat sign (E?), the pitch is lowered one half step and the resulting harmony is a minor third. Normal accidentals are not signified with parenthesis and do alter the original key.
Check for double sharps and flats. Although they are rare, especially in beginner music, a double flat will lower a pitch one full step and a double sharp will raise a pitch one full step.