o, you wanna learn how to play guitar? You've come to the right place.

It's easy to pull up some videos on YouTube to learn how to cover your favorite songs, but how many songs do you have to memorize before you can say you really know how to play the instrument? For most musicians, learning to play an instrument isn't about building up a repertoire of songs -- it's about mastering fundamental skills that you can use to play any song, any time -- or even write your own.

One of the fundamental topics you should be familiar with if you want to master playing the guitar is learning how chords work. Understanding how chords work will help you apply your knowledge of music theory across different keys and even different instruments.

If you're an absolute beginner (or even if you're not!), you might want to start here before jumping into chords -- the first article in this series on learning how to play guitar and learning music theory for guitar covers all of your basics, including the anatomy of a guitar, how to play your notes so they sound nice and clear, and a helpful finger exercise you should be comfortable with before starting to string notes together. Read more about all of those guitar fundamentals right here.

And without further ado, let's learn about chords.

Music Theory Terms: Scales, Keys, and Chords

Everything in music theory is based on a scale, or a set of musical notes grouped together and ordered by their fundamental frequency or pitch. We refer to the scale that a song is written in by calling it the “key” of the song.

So for example, consider the key of C -- we'll work with this example because C is the most common key in music, and it's easy to play on both guitar and piano.

When somebody says a song is in the key of C, what they mean is that the song only uses the notes in the C Major scale. Now, because of this, this means that all of the chords in the song are only going to be comprised from the seven notes of that scale, in this case the C Major scale. The other five notes from the complete twelve note chromatic scale are left out. That’s why knowing the parent scale or key of a song is important.

Cool. Once you have the key/scale you are using figured out, how do you know which chords to use?

Well, chords in general are made up of triads. These triads are composed of three notes played at the same time. The harmony these notes create together is what makes something a chord as opposed to just a note.

If somebody says “play me a C” you would just play them a C note all by itself. But if somebody asked you to play them a C Major, you would play them all three notes of the C Major triad simultaneously. That’s what makes a chord unique and fundamental in the composition of music. They are a way to express what type of harmony is meant to be played where. It’s just much faster to say “play a C Major” than it is to say “play me the notes C,E, and G all simultaneously”.

Chords are really just a shorthand musicians use to describe the harmonic relationship of the notes being played at one time to one another.

Playing Notes + Chords on the Guitar

If you have some experience playing guitar and are interest in learning more about the music theory behind playing chords, feel free to skip ahead to the next section on chord steps. If you're just starting out playing guitar, let's take a moment to talk about how you translate notes and chords on paper to notes and chords on your guitar.

There are many resources out there that will walk you through how to play different chords on the guitar. Before we jump into playing a chord, here's how to play a note on the guitar.

How to Play a Note on the Guitar. Image courtesy of guitar-on-the-spot.com.

When you see a diagram like this one, the line furthest to the left corresponds to the top string of the guitar and the line on the right corresponds to the bottom. The double line at the top of the diagram represents the top of the fretboard, where it connects to the head of your guitar. The horizontal lines represent the frets on the neck of the guitar.

To play the note in the diagram, press down on the string on the fret indicated and strum only that string.

Playing a chord works similarly, but you will strum all of the strings and you will likely need to press down more than one string at a time.

How to Play a Chord on the Guitar. Image courtesy of guitar-on-the-spot.com.

This chart shows what note corresponds with each string and each fret of the guitar. There are charts out there that will show you how to play different chords, but if you want to build a deeper understanding of how chords work, try figuring out how chords are played on your own. Using the chart below and the chart in the next section, try playing some triads and see how they sound!

Guitar Notes. Chart courtesy of Salinas Rambles MC.

How Chord Steps Work

So what does that mean for you? How do you apply this to playing the guitar? Well first off all it is useful to have an understanding of the note relationships different chords describe.

The following table describes many of the possible types of chords you will encounter and what scale steps are used to determine what type of chord it is. It also shows you the notes that each chord would be made up of, if the root note of each chord was on C.

How Chord Steps Work - Music Theory Chart by Anthony Stockton
How Chord Steps Work with Examples in C. Chart by Anthony Stockton.

In every key of music there is a certain order these different styles of chords are going to appear in. And this is because there are only seven notes in the scale. Each chord is based off of one of the notes of the scale.

In a C Major scale you have a chord with the root note built on every note of the C Major scale.

(C D E F G A B). And since you know the scale steps you simply count out the steps from each root note.

If you start on C and you count the major scale steps (1 3 5) and you get to the notes (C D E F G). So you know the chord built on the first step of a scale is a Major Chord.

Next you start on D and you count the major scale steps (1 3 5) and you get to the notes (D E F# G A)

But wait a second? There is no F# in the scale of C. And that is because (since we leave five notes from the chromatic scale out when we use a major scale) it is not possible to build a D Major chord in the key of C.

However! It is completely possible to build a D Minor chord in the key of C. If you start on D and you count the minor scale steps (1 ♭3 5) you get to the notes (D E F G A). Which works in the key of C! Because of this you now know that the chord built on the second scale step of the key of your song is always going to be minor.

I could continue to explain this for every single chord in order but that would just be a giant wall of text. And it would really just be me repeating the same thing over and over again. So instead I’m going to craft a handy little chart for you that shows how this works for each chord on each scale step. I will be using the C Major scale in this example, but this works the same way in every major scale.

Notes in Every C Major Chord - Music Theory Chart by Anthony Stockton
How to Play Every Chord in C Major. Chart by Anthony Stockton.

Chord Order in Major and Minor Keys

If you follow my chart, you can see that in a Major Key, the order of your chords will go like this.

Order of Chords in Major Keys - Music Theory Chart by Anthony Stockton
Order of Chords in Major Keys. Chart by Anthony Stockton.

And here is the same chart showing how that works for your 7th chords in the key of C. Your seventh chords are important because your 7th note will also determine the major and minor tonality of your chord. Major chords will have a major seventh tone, and your minor chords will have a b7 tone (flat seventh).

However, it is important to note that your fifth position chord is going to be a major triad with a flat or minor seventh. Your fifth position chord is referred to as your dominant chord and this is why-- it is a major triad with a flat 7th, or more commonly called a dominant 7th.  And this might sound unusual at first but it’s just a consequence of how your scale is counted.

For example: if you start on G, and count all the way around to a major 7th you get to an F#. But since there is no F# in the scale of C major, it means that the major triad at your fifth scale position is going to have a flat 7th. Or in this case an F. The b7 works because the b7 of your fifth position chord is going to be the fourth of your major scale that your key is based in. This happens on the fifth chord position no matter what key you might be playing in. Go ahead and replace your G Major chord with a G Dominant 7th chord next time you are playing a chord progression in C Major and you can hear how nicely the dominant 7th chord fits right into a major key yourself.

Order of 7th Chords in Major Keys - Music Theory Chart by Anthony Stockton
Order of 7th Chords in Minor Keys. Chart by Anthony Stockton.

This pattern repeats for every major scale/key that you will be playing music in. But I understand it is a lot to take in all at once. And since I’m such a nice guy, I will even cut out most of the busy work for you. I’ve explained everything in this lesson up to now with the belief that you want to understand why you are playing certain chords, instead of just knowing which chords to play when. My approach to music is always that the more you understand it the more free you are to improvise and come up with new ideas.

How Chords Work in Summarized One Simple Chart

However, I get that not everybody wants to know all the music theory behind what they are doing -- they just want to get to the fun part, playing songs! So if you are one of these people I hear you and I understand you. And as such, I have just the chart for you. The following chart shows you what chords you are supposed to play in all of your most common major and minor keys. Which makes it pretty indispensable when you are first getting the hang of guitar or when you begin writing your own music.

From my general experience the chords that are most commonly played in major keys are the major Ⅰ chord, the minor ⅵ chord, the major Ⅳ chord, and the major/dominant Ⅴ chord. These chords sound good when you put them together in pretty much any key. So if you are learning to play in a new key they are often a great place to start.

I’ve also taken the liberty of highlighting the chords I commonly see played in minor keys to help you get a quick handle on them.

Ultimate Key Cheat Sheet - Music Theory Chart by Anthony Stockton
Key Cheat Sheet. Chart by Anthony Stockton.

While I always love to tell my students that “there are no rules in music” chords are actually one of the absolute rules in music. And it’s not because using chords or understanding chords is a rule meant to constrict you. It is because we have certain names for the note relationships that make up the different chords. And as such, the names of the chords themselves become a hard and fast rule because they are describing very particular things. And if you want somebody to play a chord that sounds major you can’t ask them to play a chord made up of a different triad.

Musicians have to be able to communicate what is in their head to other musicians. Chords, and the theory underneath them, make up a most critical part of the language that is used by musicians to explain and express musical elements to one another. By understanding why chords are played where they are in relation to the key you are in, you are better able to improvise music, write and compose new music, and quickly communicate with other musicians if you enjoy playing with others.

Feb 4, 2022