A Dominant Seventh Chord is a type of chord that consists of four notes: the root, major third, perfect fifth, and minor seventh. It is typically notated as "V7" in music theory, indicating its role as the fifth chord in a key. This chord creates a strong sense of tension that resolves to the tonic chord, making it essential in many musical styles. In the key of C major, for example, the dominant seventh chord would be G7, which includes the notes G, B, D, and F. The inclusion of the minor seventh (F) adds a unique sound that distinguishes it from a regular major chord, enhancing its function in harmonic progressions.