A♭, or A flat, is a musical note that is one half step lower than A natural. It is represented by the symbol "A♭" and is commonly used in various musical scales and compositions. In the context of Western music, A♭ is part of the A♭ major scale, which consists of the notes A♭, B♭, C, D♭, E♭, F, and G. In terms of piano keys, A♭ is the black key immediately to the left of the A natural key. It is often found in the A♭ major and A♭ minor keys, which are used in many genres, including classical, jazz, and pop music. Understanding A♭ is essential for musicians when reading sheet music and playing various instruments.