In music theory, a major seventh chord contains a major seventh interval above the root. A chord lacking this interval, but otherwise containing the root, major third, and perfect fifth, is simply a major triad. For example, a C major triad (C-E-G) does not include the B note required to create a C major seventh chord (C-E-G-B). This distinction is crucial for understanding chord function and harmonic progression.
The difference between a major triad and a major seventh chord significantly impacts a composition’s sound and emotional character. A major triad sounds bright and stable, while a major seventh chord introduces a richer, more complex, and sometimes tense quality due to the dissonance introduced by the major seventh interval. This distinction allows composers to create varying levels of tension and resolution within their music. The understanding and intentional use of triads versus seventh chords became increasingly important in the development of Western harmony, particularly during the Baroque and Classical periods.
