A dominant seventh chord is a type of chord commonly used in music that consists of four notes: the root, major third, perfect fifth, and minor seventh. For example, in the chord C7, the notes are C, E, G, and B♭. This chord creates a strong sense of tension that typically resolves to a tonic chord, making it essential in many musical styles, especially in blues and jazz. The dominant seventh chord is often notated with a "7" after the root note, indicating its seventh interval. It plays a crucial role in establishing harmonic progressions, particularly in the circle of fifths. Musicians frequently use it to create movement and anticipation in their compositions.