F (musical note)
F is a musical note, the fourth above C or Fifth below C. It is also known as fa in fixed-do solfège. It has enharmonic equivalents of E and G, amongst others. When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of Middle F (F4) is approximately 349.228 Hz. See pitch (music) for a discussion of historical variations in frequency. E sharp. E () is a common enharmonic equivalent of F, but is not regarded as the same note. E is commonly found before F in the same  measure in pieces where F is in the key signature, in order to represent a diatonic, rather than a chromatic semitone; writing an F with a following F is regarded as a chromatic alteration of one scale degree. Though E and F sound the same in any 12-tone temperament, other tunings may define them as distinct pitches.