F♭, or F flat, is a musical note that is one semitone lower than F. In the context of Western music, it is often used in various scales and chords. F♭ can be notated as E, depending on the musical context, but it is distinct in its use, especially in certain keys and compositions. In music theory, F♭ is relevant in the context of key signatures and harmonic structures. It appears in some scales and can be used to create specific chords that add unique colors to a piece. Understanding F♭ helps musicians interpret and perform music accurately.