Question: if a is 440 hz what is a flat?
Answer: E♭ (musical note) E♭ (E-flat) or mi bémol is the fourth semitone of the solfège. . ... When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the E♭ above middle C (or E♭4) is approximately 311.127 Hz. See pitch (music) for a discussion of historical variations in frequency.