C-Sharp Major is a musical key that consists of seven notes: C♯, D♯, E♯, F♯, G♯, A♯, and B♯. It is often used in various genres of music, including classical, jazz, and pop. The key signature of C-Sharp Major has seven sharps, making it one of the more complex keys to play on instruments like the piano or guitar. In terms of its sound, C-Sharp Major is known for its bright and uplifting quality. Composers such as Johann Sebastian Bach and Ludwig van Beethoven have utilized this key in their works, showcasing its expressive potential. The key is also closely related to B-Flat Minor, which is its relative minor key.