Theory Study

We can use a sharp, a flat or a natural to raise or lower an individual note by a semitone. In Figure 36, the second note is F #(because of the key), but the natural sign (♮) in front of the last note of the first bar changes the note to F natural;

Similarly, the two G notes in the first bar are both G ♮, but in the second bar the sharp raises the first G to G # . The natural sign then changes the following G back to G ♮ : in other words, the natural "cancels" the sharp. In this situation, sharps, flats and naturals are called accidentals.

Figure 36: Illustration

An accidental also affects other notes of the same pitch within the same bar, as shown in Figure 37:

Or until it is replaced by another temporary change sound symbol:

The following b marked with * is redundant:

Unlike the sharps and flats in a key signature, accidentals only affect notes on the same line or in the same space within the same bar. In Figure 38, the high G here is G ♮, even though the first G is preceded by a # sign:

Figure 38: Illustration

An accidental remains valid for a tie that crosses a barline, as shown in Figure 39:

Figure 39: Illustration

But if the note is to be played again after the tie, the accidental must be rewritten. In Figure 40, the # sign marked with * is the one that must be repeated:

Figure 40: Illustration