Which chord is formed by a major triad and a major seventh?

• A. Dominant Seventh Chord
• B. Major Seventh Chord
• C. Minor Seventh
• D. Half Diminished Seventh Chord

Answer: (B)

A major triad plus a major seventh above the root forms a major seventh chord. A major triad consists of the root, a major third, and a perfect fifth. If you add the note that is a major seventh above the root, you get the chord with the notes 1, 3, 5, and the major seventh (11 semitones above the root). For example, in C major, the triad is C–E–G, and the major seventh above C is B, giving C–E–G–B, which is written as Cmaj7 (or CM7).

This differs from other seventh chords: the dominant seventh uses a minor seventh above the root (C–E–G–Bb), the minor seventh uses a minor triad with a minor seventh (C–Eb–G–Bb), and the half-diminished seventh uses a diminished triad with a minor seventh (C–Eb–Gb–Bb). Only the major triad with a major seventh produces the major seventh chord.