Seventh chords add a 7th above the triad root; major sevenths (maj7) have 11 semitones, minor sevenths (7) have 10

A seventh chord = root + third + fifth + seventh. The seventh can be major (11 semitones above root, notation: maj7) or minor (10 semitones, notation: 7). In a major key, the natural diatonic sevenths produce: Imaj7, ii7, iii7, IVmaj7, V7, vi7, vii dim7. Major seventh chords (Imaj7, IVmaj7) have a sharp, slightly tense dissonance. Minor seventh chords are mellower. Seventh chords add color and momentum to chord progressions that triads alone cannot provide.

Examples

Cmaj7: C E G B (major 7th = 11 semitones). Dm7: D F A C (minor 7th = 10 semitones). G7: G B D F (dominant 7th = minor 7th on major triad).

Assessment

Build Fmaj7 and Bm7 from scratch. Identify the interval quality of the seventh in each.