Key signature sometimes called "standard key signatures". Other scales are written either with a standard key signature and use accidental as required, or with a nonstandard key signature. Examples of the latter include the E (right hand), and F and G (left hand) used for the E diminished (E octatonic) scale in Bartók's "Crossed Hands" (no. 99, vol. 4, "Mikrokosmos"), or the B, E and F used for the D Phrygian dominant scale in Frederic Rzewski's "God to a Hungry Child". The absence of a key signature does not always mean that the music is in the key of C major /
Key signature of sharps or flats (which is the same in any clef), rather than their position on the staff. For example, if a key signature has only one sharp, it must be an F-sharp, which corresponds to a G major or an E minor key. However, in 20th-century music, there are occasional exceptions to this, where a piece uses an unorthodox or synthetic scale, where a key signature may be invented to reflect this. This may consist of a number of sharps or flats that are not the normal ones (such as a signature of just C or E), or it