Take a basic triad and add a note that is a seventh above the root to form a seventh chord. There are several different types of seventh chords, distinguished by both the type of triad and the type of seventh used. Here’s how to form the most common seventh chords in root position.
- Major Seventh chord = major triad + major seventh
- Seventh (or “dominant seventh”) chord = major triad + minor seventh
- Minor Seventh chord = minor triad + minor seventh
- Half-diminished Seventh chord = diminished triad + minor seventh
- Diminished Seventh chord = diminished triad + diminished seventh (half step lower than a minor seventh)
An easy way to remember where each seventh is:
- The major seventh is one half step below the octave.
- The minor seventh is one half step below the major seventh.
- The diminished seventh is one half step below the minor seventh.
You can step through each of the above seventh chords by starting with the major seventh and dropping one note a half step for each type:
- Major Seventh chord = Press and hold the followng keys: C – E – G – B
- Seventh (or “dominant seventh”) chord = drop the B one half-step: C – E – G – Bb
- Minor Seventh chord = drop the E a half-step: C – Eb – G – Bb
- Half-diminished Seventh chord = drop the G a half-step: C – Eb – Gb – Bb
- Diminished Seventh chord = drop Bb a half-step: C – Eb – Gb – Bbb
Click on each type to hear it played. Once you can smoothly play all of the seventh chords built on C, follow the same steps starting on D, and then up the rest of the C Major scale.
The notes for each seventh chord and notation in the Key of C are shown below.
The chord chart and rules are adapted from “Beyond Triads,” an excellent Connexions learning module developed by Catherine Schmidt-Jones.