scale). There are no sharps or flats in this scale, so the key signature for C has no sharps or flats in it. Starting on any other note requires that at least one of these notes be changed (raised or lowered) to preserve the major scale pattern. These raised or lowered notes form the key signature. Starting the pattern on D, for example, yields D-E-F-G-A-B-C-D, so the key signature for D major has two sharps--F and C.

Key signatures indicate that this applies to the section of music that follows, showing the reader which key the music