A C# Major Seventh Chord is a four-note chord that consists of the root note C#, the major third E#, the perfect fifth G#, and the major seventh B#. This chord is often used in various music genres to create a rich, harmonious sound. In music theory, the major seventh chord is denoted as C#maj7. It can be played on various instruments, including the piano and guitar, and is commonly found in jazz, pop, and classical music. Understanding this chord can enhance a musician's ability to create complex and interesting progressions.