A# Major is a musical key that consists of the notes A#, C## (which is the same as D), and E#. It is often used in various genres of music, including classical and contemporary styles. The key signature of A# Major has seven sharps, making it one of the more complex keys to play on instruments like the piano. In terms of its relative minor, A# Major is related to F# minor. This means that the two keys share the same key signature but have different tonal centers. A# Major can evoke a bright and uplifting sound, making it suitable for compositions that aim to convey joy or excitement.