Musical notation its "natural" form, which means that any sharps or flats applying to that note from the key signature or from accidentals are cancelled. Sometimes a courtesy accidental is used in music where it is not technically required, to remind the musician of what pitch the key signature requires. Following the key signature is the time signature. The time signature typically consists of two numbers, with one of the most common being "4/4". The top "4" indicates that there are four beats per measure (also called bar). The bottom "4" indicates that each of those beats are quarter notes. Measures divide
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.