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 /
E (musical note) in pieces where E is in the key signature, in order to represent a diatonic, rather than a chromatic semitone; writing an E with a following E is regarded as a chromatic alteration of one scale degree. E (musical note) E is the third note of the C major scale, and mi in fixed-do solfège. It has enharmonic equivalents of F♭ (which is by definition a diatonic semitone above E) and D, amongst others. When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of Middle E (E) is approximately 329.628 Hz.