Seventh chords by ear

Add one more note to a triad, a seventh above its root, and you have a seventh chord. Four notes instead of three means more combinations: Open Music Theory names five common seventh chords, and Earstep drills a sixth, the minor major seventh.

That sounds like a lot to tell apart, but every seventh chord is two things you can listen for separately: a triad and a seventh. This guide shows how the six are built, what makes each one recognizable, and an order to learn them in. Every sound on the page is a real piano you can play, and there are two short drills to try.

What a seventh chord is

A seventh chord is four notes that can be stacked in thirds. Stacked that way, they are the root, the third, the fifth and the seventh, each named for its distance above the root. The bottom three are a triad, and the seventh sits a third above the fifth.

Two things name a seventh chord: the quality of its triad and the quality of its seventh, measured from the root. Three sevenths are in play:

• A major seventh, 11 semitones above the root.
• A minor seventh, 10 semitones.
• A diminished seventh, a semitone smaller again. On a piano it’s the same key as a major sixth, 9 semitones up.

Combine them with the triads you know and you get the six chords:

Textbooks also use formal names that read straight off the table: the major seventh chord is a major-major seventh, the dominant seventh is a major-minor seventh, and the minor seventh is a minor-minor seventh. The diminished seventh is also called the fully diminished seventh, as opposed to the half-diminished. The first five are the common qualities Open Music Theory names; Wikipedia counts the minor major seventh among the less common ones. On C, the diminished seventh’s top note is spelled with a double flat, but on a piano it’s the key you’d usually call A.

Start with the dominant and the major seventh

The dominant seventh and the major seventh share the same major triad. The only difference is the seventh, and the two sevenths are a semitone apart: B♭ or B on top of C, E and G. There are two good ways to hear which one you have.

Listen against the octave. Imagine the root an octave higher. In a major seventh chord the seventh sits a half step below it, because a major seventh is a half step turned upside down. In a dominant seventh the seventh sits a whole step below. Stacked in thirds, as the clips here are, the seventh is the top note, so it’s the note to follow.

Listen for the tritone. The dominant seventh has a tritone, 6 semitones, between its third and its seventh: E and B♭ on C. In tonal harmony that tritone pushes toward resolution, and Open Music Theory suggests hearing the dominant seventh as “unresolved,” as if it strongly needs to move to another chord. The major seventh has no tritone at all, and Open Music Theory’s words for it are “happy and jazzy.” Use those words if they help, and replace them with your own if they don’t.

The dominant seventh is named for the note it’s usually built on, the fifth note of a major scale, called the dominant: in C major, the seventh chord on G is G7, G B D F. It was the first seventh chord to appear regularly in classical music. Major seventh chords occur on the first and fourth notes of a major scale.

Now try telling them apart. The drill plays one of the two on a root picked at random. If you miss, “Hear both” plays your pick and the right answer on the same root.

Add the minor seventh

The minor seventh chord is a minor triad with a minor seventh: C E♭ G B♭. Next to the dominant seventh, only the third is different, so the skill from major vs minor chords carries straight over: listen for the third. Unlike the dominant seventh, the minor seventh has no tritone, and its seventh sits the same whole step below the octave.

Open Music Theory’s words for it are “sad and jazzy.” In a major key, minor seventh chords occur on the second, third and sixth notes of the scale.

The two diminished sevenths

Both are built on a diminished triad, two minor thirds stacked, and they differ only in the seventh.

The half-diminished seventh adds a minor seventh: C E♭ G♭ B♭. Next to the minor seventh chord, only the fifth is lower, and its other name says exactly that: minor seventh flat five, written m7♭5. It occurs on the seventh note of a major scale.

The diminished seventh lowers the seventh by one more semitone: C E♭ G♭ B𝄫. That makes it three minor thirds stacked, and one more minor third would bring you back to the root, so it divides the octave into four equal parts. Like the augmented triad, each of its inversions sounds like another diminished seventh in root position. It occurs on the seventh note of the harmonic minor scale.

Despite the shared name, Wikipedia notes, the two sound considerably different. Two clues tell them apart:

• Count the tritones. The half-diminished seventh has one, between its root and fifth, like the diminished triad. The diminished seventh has two, a minor third apart.
• Listen against the octave. The half-diminished seventh’s top note sits a whole step below the root’s octave, like the minor seventh’s. The diminished seventh’s sits three semitones below, a minor third.

Open Music Theory offers “scary and jazzy” for the half-diminished seventh and “very scary” for the diminished seventh.

The minor major seventh

The last of the six is the minor major seventh: a minor triad with a major seventh, C E♭ G B. It differs from the minor seventh only in its seventh, and from the major seventh only in its third. Its upper three notes, E♭ G B, form an augmented triad, which is one way to remember its sound. It’s the seventh chord on the first note of the harmonic minor scale, and Wikipedia reports a nickname, “the Hitchcock chord,” from Bernard Herrmann’s use of it in film scores, most famously Psycho.

How to listen to a seventh chord

Put the clues together and a seventh chord comes apart into two questions:

1. Which triad is underneath? In root position the triad is the bottom three notes. Major, minor or diminished narrows the six chords down to two.
2. How far is the seventh from the octave? A half step means a major seventh, a whole step a minor seventh, a minor third a diminished seventh.

The tritone is a cross-check. The dominant, half-diminished and diminished sevenths have at least one; the major, minor and minor major sevenths have none. In Earstep every seventh chord plays in root position, all four notes together, so the seventh is always the top note.

A learning order

The Seventh chords path in Earstep has 5 levels and adds one chord at a time:

1. “Dominant or major seventh”: one major triad, two different sevenths.
2. “Add the minor seventh”: three answers.
3. “Add half-diminished”: four answers.
4. “Add the diminished seventh”: five answers.
5. “Every seventh chord”: all six, with the minor major seventh.

Notice that each new chord is one semitone away from one you already know. The minor seventh is the dominant seventh with its third lowered, the half-diminished is the minor seventh with its fifth lowered, the diminished seventh is the half-diminished with its seventh lowered, and the minor major seventh is the minor seventh with its seventh raised. Each level asks you to hear one more note move.

The path opens once you’ve passed level 2 of Triads, so the triads come first; chord inversions open at the same point. Here is level 3, four chords at once:

If it went well, add the diminished seventh next. If it didn’t, go back to the first pair for a few days; the later chords are easier to place once the dominant and the major seventh feel obvious.

Sources

• Open Music Theory: Seventh Chords: four notes stacked in thirds; the five common qualities, their formal and common names, and how each combines a triad and a seventh; where each occurs in major and minor keys; the words learners often pair with each.
• Open Music Theory: Intervals: how intervals invert, a major seventh into a minor second.
• Open Music Theory: Equal Divisions of the Octave: minor thirds dividing the octave and outlining a diminished seventh chord.
• Seventh chord, Wikipedia: a triad plus a seventh; the five common types and the less common minor major seventh; the major seventh as an inverted minor second; the dominant seventh as the first seventh chord in regular use.
• Dominant seventh chord and Tritone, Wikipedia: the dominant built on the fifth degree; which seventh chords contain tritones, and how tritones push toward resolution.
• Minor seventh chord and Half-diminished seventh chord, Wikipedia: where each occurs; the name minor seventh flat five; how the half-diminished differs from the diminished seventh.
• Diminished seventh chord and Minor major seventh chord, Wikipedia: three stacked minor thirds and symmetrical inversions; the diminished seventh as a major sixth on the keyboard; the harmonic minor scale; the nickname.