Have you ever been listening to a beautiful piece of jazz music and wondered how the musicians create that spellbinding, ethereal, never truly settled sound? How do they create a feeling of unending motion, while still having resolutions here and there? The answer is through clever use of seventh chords.

Seventh chords are the first addition to triads. Triads are the most basic chords we learn while taking piano lessons, and function as the base of more complicated chords, which begin with seventh chords. Seventh chords are just one additional note on top of a triad (which technically makes it a tetrad, though very few people still use that language).

Types of Seventh Chords

The four kinds of naturally occurring seventh chords are the major seventh, the dominant seventh, the minor seventh, and the half-diminished seventh. Check out the image above for all naturally occurring seventh chords in C major. Not naturally occurring seventh chords include the fully diminished seventh, the minor-major seventh, and the augmented seventh.

Naturally occurring means that the notes used to create the seventh chord belong entirely to a key, and none of the notes are altered. For more info about keys, check out this blog!

Music Chords: Vocabulary & Background

It would be valuable to refresh your memory on intervals, specifically by reading our blog on thirds and sevenths, but here is a quick review below.

Thirds are the building block for chords. There are three kinds of thirds used in triads and seventh chords -- a major third, which is made up of four half-steps (or two whole-steps); a minor third, which is made up of three half-steps; and a diminished third, which is made up of two half-steps. Below, you’ll find an example of several major, minor, and diminished thirds, as well as their sound. (Hint: read these blogs for a review on sheet music or keyboard layout!)

Sevenths are the intervals between the root note and the new added note, which give these particular chords their name. There are a few seventh intervals used here, a major seventh (eleven half-steps), a minor seventh (ten half-steps), and a diminished seventh (nine half-steps). Below you’ll find several examples of seventh intervals, as well as their sounds.

Check out this intervals reference table for all intervals in case you’re curious.

Major Seventh

The major seventh is a major triad with a major third on top. They naturally occur by making seventh chords from the 1st and 4th scale degrees. The 1st and 4th scale degrees are C and F, so those chords are written as Cmaj7 and Fmaj7. In older prints of jazz standards, you may find a triangle symbol written instead of the abbreviation maj. For example: C△7 means the same thing as Cmaj7. This chord is named this way because it is a major triad, and the interval made by the added note with the root is a major seventh.

The sound of a major seventh:

A song that beautifully uses the sound of a major seventh is “Something,” by The Beatles.

Dominant Seventh

The dominant seventh is a major triad with a minor third on top. They naturally occur only once in a key – from the 5th scale degree. However, they are the most commonly used chord on piano (and other instruments, too!), so they are usually written as just the name of the chord with a number seven after. The 5th scale degree in C is G, so the seventh chord is G7. This chord is named this way because the only natural occurrence of it is from the 5th scale degree, also called the Dominant.

The sound of a dominant seventh:

The dominant seventh is a very commonly occurring chord, but a great example of it is in blues music. Almost every chord in the blues progression is a dominant seventh chord, and it is an identifying sound of the genre. Here is a good example, in “The Sky is Crying,” by Gary B.B. Coleman.

Minor Seventh

The minor seventh is a minor triad with a minor seventh on top. They naturally occur from three scale degrees – the 2nd, 3rd, and 6th. Those scale degrees end up being D, E, and A, so the seventh chords from those notes are written as Dm7 (or D-7, the – being a common symbol for minor in notation), Em7, and Am7. This chord is named this way because it is built from a minor triad, and the interval made from the root to the added note is a minor seventh.

The sound of a minor seventh:

A good example of a song that uses a minor seventh chord is “Autumn Leaves,” which starts off with a minor seventh chord right after the violin intro.

Half-Diminished Seventh chords

If you’ve been paying attention, and I hope you have, then two major seventh chords, plus one dominant seventh chords, plus three minor seventh chords only equals six chords. And since there are seven scale degrees, that leaves just one scale degree left – the seventh scale degree.

From the seventh scale degree, a half-diminished seventh chord is built – made up of a diminished triad plus a major third. The 7th scale degree is B, so the chords is a B half-diminished 7.

There are a couple of common notations for a half-diminished chord, including Bø7 and Bm7b5. The first notation, Bø7, is written this way because the degree symbol is a common shorthand for a diminished chord, but since this seventh is only half-diminished, there is a line through it. The second notation is written this way because a half-diminished seventh chord only differs from a minor seventh chord by one note – the fifth of the chord. You flat the fifth of a minor seventh chord, and you get a half-diminished seventh chord. For a review of sharps and flats, check out this blog! This chord is named this way because it is built from a diminished chord, but the interval made from the root to the added note is a minor seventh, so it is only half diminished.

The sound of a half-diminished seventh:

A song that uses the half-diminished seventh includes “Because” by The Beatles, where the second chord is a D#m7b5.

Fully Diminished Seventh Chords

The first of the not naturally occurring sevenths is the fully diminished (or simply diminished) seventh. It is made up of a diminished triad with a minor third on top. This chord is written this way: Co7. The degree symbol is a common shorthand for diminished chords, and as this one is fully diminished, there is no line through it. This chord is named this way because it is built from a diminished triad, and the interval made from the root note to the added note is a diminished seventh.

The sound of a diminished seventh:

A song that uses the fully-diminished seventh is “Georgia on my Mind,” performed by Ray Charles, which uses a C#o7about halfway through the progression.

Minor-Major Seventh CHords

The next not naturally occurring seventh chord is the minor-major seventh. It is a very uncommonly used chord. It is made up of a minor triad with a major third on top. It is notated as Cminmaj7 (kind of annoying to write, but it’s so uncommon that no shorthand has been created for it yet). It is so named because it is made up of a minor triad, and the interval made from the root note to the added note is a major seventh.

The sound of a minor-major seventh:

A song that includes the minor major seventh is the “James Bond theme,” where the very last chord is a minmaj7th.

Augmented Seventh Chords

The last of the not naturally occurring seventh chords is an augmented seventh. It is built from an augmented triad with a diminished third on top. It is notated either as C+7 or C7#5. The plus is a common shorthand for augmented chords, and the #5 is used as the augmented seventh only differs from the dominant seventh by one note – the fifth of the chord. It is so named because it is built from an augmented triad, and the interval made from the root note to the added note is a minor seventh.

The previously mentioned dominant seventh (or just seventh) chord also has a minor seventh in it, and as the sound of an augmented seventh, as well as its function in many chord progressions, it is very similar to a dominant seventh. It also is simply named as the augmented seventh.

The sound of an augmented seventh:

A song that uses the augmented seventh is “When You Wish Upon a Star,” from Disney’s Pinocchio. The augmented seventh is the second chord in the progression.

Seventh chords: wrap-up

Using seventh chords effectively can really upgrade your playing from just triads. At Boston Piano Lessons, after a good foundation of understanding chords and harmony is built from using triads, your piano instructor will immediately dive into seventh chords, as that is the next step to level-up your abilities when learning piano as a beginner as well as your understanding of music in general.

Also, jazz, as well as many other genres of music, can’t effectively be played without an understanding of seventh chords, so knowing all your seventh chords and where they go in chord progressions unlocks a whole new world of piano playing. Though seventh chords are complicated at first, with some practice, and a little instruction, you too can be a jazz piano cat!

Seventh Wonders of the Chord: How to Make & Use Seventh Chords on Piano