Key signature key signatures showing sharps or flats on both octaves for notes which fall within the staff. An accidental is an exception to the key signature, applying only to the measure and octave in which it appears. Although a key signature may be written using any combination of sharp and flat symbols, the most common series of thirteen homogeneous key signatures—ranging from six flats to six sharps, with each successive flat or sharp placed on the note a perfect fifth below or above, respectively, the previous one—is assumed in much of this article. A piece scored using a single diatonic key
Key signature vice versa, the old key signature is cancelled with the appropriate number of naturals before the new one is inserted; but many more recent publications (whether of newer music or newer editions of older music) dispense with the naturals and simply insert the new signature. Similarly, when a signature with either flats or sharps in it changes to a smaller signature of the same type, strict application of tradition or convention would require that naturals first be used to cancel just those flats or sharps that are being subtracted in the new signature before the new signature itself is written;