Key signature may consist of one or more sharps combined with one or more flats (such as a signature containing both F and B). Key signatures of this kind can be found in the music of Béla Bartók, for example. The effect of a key signature continues throughout a piece or movement, unless explicitly cancelled by another key signature. For example, if a five-sharp key signature is placed at the beginning of a piece, every A in the piece in any octave will be played as A sharp, unless preceded by an accidental (for instance, the A in scale 2 illustrated –
Key signature be changed at any time in a piece, usually at the beginning of a measure, simply by notating the new signature, although if the new signature has no sharps or flats, a signature of naturals, as shown, is needed to cancel the preceding signature. If a change in signature occurs at the start of a new line on the page, where a signature would normally appear anyway, the new signature is customarily repeated at the end of the previous line to make the change more conspicuous. In traditional use, when the key signature change goes from sharps to flats or