C# Major is a musical key that consists of the 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 is known for its bright and uplifting sound, making it a popular choice for composers and songwriters. In terms of its scale, C# Major is the relative major of the B# minor scale. The key signature of C# Major contains seven sharps, which can be challenging for some musicians. Instruments like the piano and guitar can easily play in this key, allowing for a wide range of expressive possibilities.