B Flat is a musical note that is one semitone lower than B and one semitone higher than A. It is commonly used in various musical scales and is a fundamental note in Western music. In the context of a piano, B Flat is played by pressing the black key immediately to the left of B. In terms of musical notation, B Flat is represented by a note on the second line of the treble clef with a flat symbol (♭) placed before it. This note is significant in many musical genres, including jazz, classical, and blues, often serving as a key center for compositions.