A Dominant Seventh chord is a type of seventh chord that consists of four notes: the root, major third, perfect fifth, and minor seventh. It is often notated as "7" and is commonly used in various music genres, particularly in jazz and blues. This chord creates a sense of tension that typically resolves to a tonic chord, making it essential in establishing harmonic movement. In the key of C major, the Dominant Seventh chord would be C7, which includes the notes C, E, G, and B♭. The presence of the minor seventh (B♭) gives it a distinctive sound that differentiates it from a major or minor chord. This characteristic makes the Dominant Seventh a powerful tool for composers and musicians.