Augmented & Diminished Chords

There are more chords out there than just the most common major and minor chords. Have you ever seen the plus (+) or degree (°) symbol next to a chord and wondered what it meant? How about in jazz notation with a m7b5, or a 7#5? These are diminished and augmented chords, and knowing what they are and where they belong can help add new flavors to your playing, as well as unlock many songs in which these chords are already used.

Read on to learn how to identify diminished and augmented chords, and ask about how to play them at your next class with Boston Piano Lessons!

Thirds: the building blocks of chords

If you need a deeper dive into chords, here’s a great blog post! Don’t worry, there’s a quick review coming.

The most basic and most common types of chords are called triads – as they are made up of three notes. Chords are built using two kinds of thirds – an interval – called major thirds and minor thirds. Major thirds are made up of four half-steps (or two whole steps) - for example, C to E, E to G#, and F to A. Minor thirds are made up of three half-steps (or one and a half whole steps) - for example, C to Eb, E to G, or F to Ab.

As triads, and 95% of chords that you’ll find, are made up of thirds, it is essential to know these few vocabulary words when talking about chords. Though it is possible to just memorize what each chords looks like, it will quickly become unwieldy to do so as there are so many chords out there, and once you go beyond triads to seventh chords, there are even more – therefore, it is much more useful to understand how chords are formed, so that instead of rote memorization, you can proceed with the ability to play any chord as you understand how they are made.

What are Diminished Chords?

Diminished triads are built off two minor thirds stacked on top of each other. They are called diminished triads as the interval between the first note (the root) and the last note (the fifth) is a diminished fifth. For more info, read up on the extended intervals section of the intervals blog!

Pictured below are all twelve diminished triads.

In each key, there are seven notes. From each of those seven notes, you can build chords using only the notes included in the key. This results in three major chords, three minor chords, and one diminished chord. Here is a more in-depth explanation of keys, scale degrees, and how chords fit together, but below is an image of all the chords in the key of C major.

As you can see, unlike major and minor chords, which are the most common chords, diminished chords are much rarer as they appear less in a key.

Often, you’ll find diminished chords in their seventh chord flavors. There are two kinds of these chords – half-diminished seventh chords and fully diminished seventh chords.

Half-diminished seventh chords

Half-diminished seventh chords are the most common, and have a major third stacked on top of two minor thirds. In Jazz notation, they are either written as -7b5 chords or, in older printings, as a degree symbol (which means diminished in musical notation) with a line through it. They are most commonly used as a passing chord – an optional chord in between two other chords – when moving between a higher chord to a lower chord to make the transition between the chords smoother. All half-diminished seventh chords are pictured below:

Fully diminished seventh chords

Fully diminished seventh chords are even rarer, and they are made up of three minor thirds stacked on top of one another. They are notated as o in both jazz and classical notation. These chords are most commonly used as passing chords when moving between a lower chord and a higher chord. All fully diminished chords are pictured below.

Popular songs that use diminished chords

Here are a few examples:

“Somewhere Over the Rainbow,” from the Wizard of Oz soundtrack, uses a C# half-diminished seventh chord:

“Michelle,” by The Beatles, uses a few diminished chords of both triad and seventh chord flavors:

“Georgia On My Mind,” performed by Ray Charles, uses a fully diminished seventh chord:

What are Augmented Chords?

Augmented triads are built off two major thirds stacked on top of one another. They are so named because the interval between the first note (the root) and the last note (the fifth) is an augmented fifth. For more info, read up on the extended intervals section of the intervals blog!

Pictured below are all the augmented triads.

If you’ve read the blog on keys, scale degrees, and the basics of improvisation, you’ll know that every key has seven notes, and therefore there are seven (7, not seventh!) chords that belong in that key. There are three major, three minor, and one diminished chord that belong in each key. Augmented chords do not occur naturally in any key! Therefore, they are the rarest chord of all.

Augmented seventh chords

There is only one type of augmented seventh chord, which is made up of a diminished third – two half steps (or one whole-step) – stacked on top of two major thirds (the augmented triad).

You can try other combinations of thirds on top of the augmented triad – but they all sound so dissonant that the only one that is in any use at all is the augmented seventh chord. If you notice, the diminished seventh chords come in two flavors and so have a qualifier, being either half- or fully diminished seventh chords, but as augmented seventh chords only come in one flavor they don’t require a qualifier.

Augmented seventh chords are quite uncommon, but they are occasionally used as a replacement for a dominant seventh chord to be a little more interesting.

Pictured below are all the augmented seventh chords.

Songs that use augmented chords

“Oh! Darling,” by the Beatles, uses an augmented chord to great effect:

“Someday My Prince Will Come,” from the Snow White and the Seven Dwarfs soundtrack, uses an augmented chord:

“You’ve Got a Friend in Me,” from the Toy Story soundtrack, uses a few augmented seventh chords:

Diminished & Augmented Chords: A summary

Though much rarer than either major and minor chords, it is nonetheless important to know about augmented and diminished chords, and their seventh chord counterparts, the half-diminished, fully diminished, and augmented seventh chords. Just knowing what those complicated chord symbols mean and being able to play them correctly unlocks so many amazing songs. In addition, knowing what augmented and diminished chords are, what they sound like, and when to use them can drastically improve the complexity of your improvisations and compositions.

And, more importantly, this blog, along with the major and minor triads blog as well as the seventh chords blog, completes your knowledge of basic chords. This is more than enough information to play pop songs, and gets you pretty far into knowing jazz – enough to figure out the rest on your own! You can always learn more by signing up for private piano lessons with a teacher of course, and find new applications for these and many more chords, but these guides get you pretty far in.