Music & Entertainment

Music 101: What Is a Chord? Learn the Difference Between Major Chords vs. Minor Chords

Written by MasterClass

Apr 29, 2019 • 7 min read

Instrumental music consists of three principal elements: rhythm, melody, and harmony. The last of these elements—harmony—is represented via chords.

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What Is a Chord?

A chord is a group of two or more notes occupying the same time duration in a piece of music. These notes do not have to be played simultaneously, and they don’t all have to be played by the same instrument. As such, a chord could be played by a single musician strumming the six strings of her guitar, or a chord could be played by an orchestra featuring 50 individual players playing one note each.

Most chords contain three or four pitches, but some styles of music—most notably, jazz—favor chords with five pitches, six pitches or more.

What Are the Basic Chords?

The primary chords of Western music are the “major triad” and the “minor triad.” Per their names, these are three-note chords built on specific degrees of a major scale and a minor scale, respectively.

The major scale consists of 7 notes. Starting from the lowest note, and going up, they are:

1—the “root” of the scale
2—a whole step up from the root
3—a whole step up from the 2nd
4—a half step up from the 3rd
5—a whole step up from the 4th
6—a whole step up from the 5th
7—a whole step up from the 6th

Then, with one more half step, we get back to the “root”—only now we’re an octave higher than we were before.

The second most important building block of Western music is the natural minor scale. This is similar to a major scale, but with a few half steps where there were previously whole steps.

1—the “root” of the scale
2—a whole step up from the root
3—a half step up from the 2nd
4—a whole step up from the 3rd
5—a whole step up from the 4th
6—a half step up from the 5th
7—a whole step up from the 6th

And then we need one final whole step to get back to the root—but again it’s an octave higher than where we began. In a natural minor scale, we often call the 3rd, 6th, and 7th degrees as “flat degrees.” Therefore, we might say that the notes of a minor scale are:

1 - 2 - b3 - 4 - 5 - b6 - b7

Triads are built on three specific scale degrees: the root, the third, and the fifth. To see this in practice, consider the following:

  • C major triad consists of the root, third, and fifth of a C major scale. That would be C, E, and G
  • G major triad consists of the root, third, and fifth of a G major scale. That would be G, B, and D
  • F# minor triad consists of the root, third, and fifth of an F# minor scale. That would be F#, A, and C#

Learn about scales here.

Major Chords vs. Minor Chords

Remember that triads are three-note chords. There is one single note that distinguishes a major chord from a minor chord: the third.

  • A major chord has what’s called a “natural third.” It’s the third degree of the chord’s respective major scale.
  • A minor chord has what’s called either a “minor third” or a “flat third.” It’s the third degree of the chord’s respective minor scale.

What Are Diminished Chords?

Before we go any further, we need to learn about one more type of triad: a diminished triad. This three-note chord contains a root, a flat third, and a flat fifth. Diminished triads sound ominous and unresolved, like the soundtrack you’d hear in a Halloween haunted house.

By using these three types of triads—major, minor, and diminished—we can create triads from every degree of the major and minor scale.

Expressing Chords with Roman Numerals

We can build triads starting on every note of a major scale. We notate these chords using Roman numerals, as follows:

  • I—a major triad starting on the 1st degree of the scale
  • ii—a minor triad starting on the 2nd degree of the scale
  • iii—a minor triad starting on the 3nd degree of the scale
  • IV—a major triad starting on the 4th degree of the scale
  • V—a major triad starting on the 5th degree of the scale
  • vi—a minor triad starting on the 6th degree of the scale
  • viiº—a diminished triad starting on the 7th degree of the scale

When we assign these Roman numerals to specific keys, we get a specific set of chords. For instance, let’s take Bb major. The chords associated with that scale are:

  • Bb major (the I)
  • C minor (the ii)
  • D minor (the iii)
  • Eb major (the IV)
  • F major (the V)
  • G minor (the vi)
  • A diminished (the viiº)

If you’re working in the natural minor scale, these are the chords built off each degree of that scale:

  • i—a minor triad starting on the 1st degree of the scale
  • iiº—a diminished triad starting on the 2nd degree of the scale
  • bIII—a major triad starting on the 3rd degree of the scale (which we sometimes call the flat third degree)
  • iv—a minor triad starting on the 4th degree of the scale
  • V—a major triad starting on the 5th degree of the scale
  • bVI—a major triad starting on the 6th degree of the scale (which we sometimes call the flat sixth degree)
  • bVII—a major triad starting on the 7th degree of the scale (which we sometimes call the flat seventh degree)

Now let’s assign these Roman numerals to an actual minor key to see how this works in real life. Let’s use the C natural minor scale. The chords associated with it are:

  • C minor (the i)
  • D diminished (the iiº)
  • Eb major (the bIII)
  • F minor (the iv)
  • G major (the V)
  • Ab major (the bVI)
  • Bb major (the bVII)

Seventh Chords and Beyond

If you want to use four-note chords and beyond, you’ll need to add a scale degree that isn’t a root, third, or fifth. The most common four-note chord is the seventh chord, where the seventh scale degree is added to a major or minor triad. There are three main types of seventh chords:

  • Major seventh chord. This takes a major triad and adds the seventh degree of the major scale. You notate a C major seventh chord as C maj 7, CM7, or even C△7. Its notes are C - E - G - B.
  • Minor seventh chord. This takes a minor triad and adds the seventh degree of the minor scale (aka the flat seventh). You notate a C minor seventh chord as Cm7 or C-7. Its notes are C - Eb - G - Bb.
  • Seventh chord (sometimes called a dominant seventh chord). This combines a major triad with the seventh degree of a minor scale. That means it has a major 3rd but a minor 7th. It’s probably the most common of the 7th chords, and a C seventh chord is simply notated C7. Its notes are C - E - G - Bb.

There is one more type of seventh chord—the “minor major seventh chord.” It’s the opposite of a regular 7th chord in that it has a minor third but a major 7th. You’d notate C minor major seventh as Cm(maj7). Its notes are C - Eb - G - B. This type of chord is rarely used, but it’s sometimes heard in twentieth-century suspense music, like in a cheesy spy movie or the broadcast TV version of Batman.

Other Important Chords to Know

Major chords, minor chords, diminished chords, 6th chords, 7th chords, and 9th chords are perhaps the most commonly used chords in Western music, but they aren’t the only ones out there.

  • A sixth chord is like a seventh chord, only with the sixth scale degree added instead of the 7th scale degree. As such, a C sixth chord is written C6 and contains the notes C - E - G - A.
  • A ninth chord is a seventh chord with one extra note added. That note is called the 9th—which is the same thing as the 2nd scale degree, only an octave higher. In the key of C, the 2nd scale degree is D. Therefore, the 9th scale degree is also D. When you see the chord symbol C9, that means you should play the notes C - E - G - Bb - D.
  • A minor ninth chord is just like a ninth chord, only it’s based on a minor triad. C minor ninth is written as Cm9 or C-9, and its notes are C - Eb - G - Bb - D.