Ever wonder why certain chords sound good together and other chords don’t quite fit in? You may say to yourself, “I’ve learned how to play a G, C, D, E, A and a few others, but I can’t put together all of these chords and make a song out of them. They just don’t sound right together.”
Maybe you’ve even learned some minor chords and you try to throw them into the mix every now and then. But when you try to come up with a chord progression that makes sense, you fall flat. Pun intended ? You need a lesson on some music theory.
The chords that sound good together are made up of notes that makes sense harmonically. The notes of these chords are derived from a scale (usually the Major scale). The chords use something called diatonic harmony.
I’m going to teach you the theory behind what makes certain guitar chords sound good together, why certain combinations don’t sound good, and how you can use this information to become a better musician.
This information is powerful!
You’ll be able to write songs in any key, know why a certain chord should be major or minor within that key, and be able to express a certain type of mood with certain chord combinations. Sound interesting? It should.
Do you want to write a happy song? I’ve got a chord combination for that. Do you want to write a sad song? I’ve got a chord combination for that. How about a mean sounding song? Do you want to write a mellow song? I’ve got chords for that too!
OK enough talk. Let’s dig into it already. There is a certain name for this subject I’m talking about. What are we really talking about here?
This Subject Is Called “Diatonic Harmony”
Maybe you’re asking “what the heck is diatonic harmony?” Don’t worry I’ll explain. First let’s start by looking at something little more simple…
The Major Scale = Our Starting Point
Just to clarify, a scale is a collection of notes played in sequence. Most scales have a minimum of five notes. The major scale has seven notes. The major scale is a “happy” or “bright” sounding scale. It’s the classic “do-re-mi” scale that you probably learned in in middle school.
Every scale is based around a root note. The root note is the note the scale is centered upon. In other words the scale begins on that note, and ends with the note right before that one. The scale starts over again on the root note, just an octave higher.
It’s called an octave higher because it’s 8 tones away from the root. An A note has a frequency of 440 Hz, but another A, an octave higher is twice the frequency at 880 Hz.
For example, the G major scale starts on a G note and ends on an F-sharp note. After the F-sharp comes another G note, just an octave higher. See how this works?
For the sake of this article let’s use the C-major scale as our guinea pig. The C-major scale has no sharps or flats, so it’s the easiest one to use for the sake of teaching. It has seven notes starting with C of course, then D, E, F, G, A, and B. Then back to C, an octave higher.
Defining A “Chord.” What Exactly Is It?
OK so now we know the scale is. But we haven’t even defined what a chord is yet have we? Let’s do that. This may seem simplistic, but it’s necessary.
A chord is a combination of a minimum of three notes played at the same time. Just like a scale, chords are assigned a letter based on their root note. They are also named based upon the formula of intervals created by the notes in relation to to the root.
For example, a C major chord has the C, E, and G notes. Other than the root there are 2 notes. The interval from a C and an E is called a major third.
All chords or scales that have a major 3rd are called major. All scales that have a minor 3rd are called minor. The 3rd interval is an important note in determining the tonality and thus, the mood of a chord or scale. The term major or minor is sometimes referred to as the “quality.” Major and minor aren’t the only chord qualities as you will see later.
Anyway, let’s get back to our C major chord. Apart from the C and the E, there is a G, which is a perfect fifth interval away from the C. The fifth interval can either be perfect, augmented, or diminished. I don’t want to talk much about the fifth interval in this article. That’s a topic for another article.
Bringing It All Together…Diatonic Chords
You may be wondering why we’re talking scales when all we want to know is which chords sound good together. What do scales have to do with anything? Here’s the answer.
We get the notes we need to form the chords, from the scale of the key that we’re playing in. We limit ourselves to only using the notes out of the scale of the key you’re playing in, you end up with chord combinations that sound good together.
Here is the C major scale.
If we only use notes from this scale to form chords, we’ll have a set of diatonic chords to the key of C major, and they’ll all make sense when you hear them played together.
The term “diatonic” means that it only uses notes from the key you’re playing in. For example, if we’re playing in the key of F major, and we start playing notes that aren’t in the key of F major, we’re not playing notes that are diatonic. “Diatonic to” basically means “within the bounds of” the scale your key is based upon.
If you play notes that are not diatonic to the key you’re playing in, you’re going to be able to recognize them with your ear. There are exceptions to the rule of course, but the majority of times, you’ll know when a note is “out of key” or “not diatonic.”
Now, Let’s Build Some Diatonic Chords
Diatonic chords are built by stacking every other scale note on top of each other. These intervals between notes usually come out as major or minor third intervals. This concept is sometimes referred to as “stacking thirds” on top of each other.
Here we can see that for the C Major scale we have the C, E, and G notes stacked on top of each other to form a C Major chord. It’s a major chord, because the E is a major third away (four semitones) from the C.
C Triad chord formed from stacking the 3 notes above on top of each other, and played at the same time.
What happens if we shift the root note up to the D and stack every other note on top of each other? We end up with a D minor chord. Why minor? Because the third in this chord is a minor third away (three semitones) from the root. An F is a minor third away from the D.
C Major scale with boxes around the root D, F, and A notes.
The D minor triad with a root (D), minor third (F), and perfect fifth (A).
Let’s figure out what every diatonic chord turns out to be, for this c major scale.
Each root note forms what is called a scale degree. When writing chord progressions, each degree of the scale is represented in Roman numerals. So far the chords I’ve shown you only have three notes. Chords with 3 notes are called “triads.” They contain a root, a third, and a fifth. Here are the triad chords created for each degree of the major scale.
Hopefully this is starting to make some sense!
Now we have a bunch of major and minor chords. The only exception is on the 7th degree, where there is a diminished chord. The diminished chord has a minor third interval and a diminished fifth interval. It’s not a very commonly used chord in popular music, but it’s necessary to know.
When you look at the table above, you can start creating chord combinations that make sense. I guarantee you, that if you pick a key, and play diatonic chords of that key, they’ll always sound good together. They’ll sound like they fit together.
Go ahead and play each of these chords, in order, and see if it doesn’t sound like the major scale being played, in a “chordal” or harmonic way. It does doesn’t it? Actually, I’ll play them for you. Have a listen. These are the triad chords in the key of C Major.
Now what happens when we mix them up, and only play certain degrees of the scale? We get chord progressions that make sense and sound like they fit together.
We can then label these progressions with numbers, such as a 1-4-5, or a 1-5-6-4. In jazz, the 2-5-1 is extremely common. Roman numerals can also be used to name these chord progressions, such as I-IV-V, I-V-iv-V, ii-V-I, etc. The major chords are indicated in upper case numerals.
The 1-5-6-4 is probably the most common chord progression there is in popular music. It’s used In countless pop, rock, and country songs. Let’s examine that progression in the key of C, shall we?
Here are the diatonic chords in the key of C.
|C Major Chords||C||Dm||Em||F||G||Am||Bdim||C|
So the 1-5-6-4 progression in C Major would be C-G-Am-F. How about a 1-4-5 in C Major? It would be C-F-G. See how this works yet?
What if we decide to switch keys? Let’s say G Major. The 1-5-6-4 is G-D-Em-C
Here are diatonic chords of G Major.
|G Major Chords||G||Am||Bm||C||D||Em||F# dim||G|
A Quick Word About Minor Keys
The same pattern applies to all major keys. The minor keys are the same. All you would do is just shift up the root note to the natural minor, which happens to be the 6th degree of the major scale. This would be the Aeolian mode, but we’ll cover modes later. (Too complex).
What About Seventh Chords?
Up to this point in the article we’ve only been discussing triads, or chords with three notes. When we start talking about chords with four notes in them, we’re talking about seventh chords.
If you remember from our diagram before you would see that when we stack three notes of diatonic thirds on top of each other we end up with diatonic triads. To get diatonic seventh chords you just add an extra note a third higher on top of the fifth. For the key of C Major, seventh chords would look like this.
Most of these chords have the same quality as triads, except they have 7s at the end of their names. Instead of C Major, it’s now C Major 7. Instead of D minor, it’s now D minor 7 and so on.
Here I am playing all of the diatonic 7th chords in C Major.
Here are the diatonic chord qualities of the 7th chords of the major scale.
A Word About 7th Chords
7th chords are sometimes referred to as “jazz guitar chords”. The reason for this is because the added 7th creates a more mellow type of sound, usually associated with jazz. If you played a 2-5-1 progression (very common in jazz) in C Major, the progression would be Dm7-G7-CMaj7. Here’s what that sounds like.
Dominant and “Half-Diminished” Chords
We do encounter a couple of new chord qualities, when we add 7ths into the mix. I’m talking about the dominant chord on the 5th degree of the scale, and the minor-seven-flat-five chord on the 7th degree of the scale.
The more notes you add to the chord, the more complex they can get. And that’s what we end up with here…more complexity. The dominant chord is somewhat of a combination of major and minor chord. It has a major third but a minor seventh in it. This combination of intervals gives it a “sassy” or “bluesy” sound. Jazz and blues tunes use the dominant chord, a lot.
The minor-seven-flat-five chord on the 7th degree is the same diminished chord we used when we were looking at triads, except with a flat seventh added on to it. This chord is also called a half-diminished chord, because “half” of the chord is diminished.
Chords, Chord Progressions, and “Moods”
As I said in the beginning of this article, there are certain chords and combinations you play to express certain moods. Of course, this is all up for interpretation and only you can judge for yourself which chord progressions express which moods, but I’ll give you some of my opinions and play examples. for you.
Chords For “Sad” or “Dark” Moods
Traditionally the minor chords are known to be best at expressing the sad and dark moods, but I think the chord progressions with major chords can also be used to express sad moods, especially when played slowly. Ever hear the song “Philadelphia” by Neil Young?
Chords for Happy and Bright Moods
As I said previously, many other factors, other than chords and chord progressions determine the mood of a song, BUT, happy and bright moods are generally expressed in major and dominant chords.
Chords For “Bluesy,” Jazzy, Or Mellow Moods
To express mellow and sassy moods, we’re definitely going to be talking about 7th chords and beyond. This topic is beyond the scope of this article, but for jazz and blues, we play major, minor, and dominant chords with all sorts of extensions.
I’m talking about 7th chords, 9th chords, 13th chords, as well as altered chords with augmented or diminished fifths, raised or lowered 9ths, and so on.
As I said, we’re venturing into another realm when we discuss blues and jazz. To learn how to get start on blues, check out my article on blues guitar chords and how to get started in the blues.
So, the question you had was “what makes certain chords sound good together, and why?” The answer to this question is not exactly a super simple one, but I hope I did a fairly decent job in providing an answer.
- Every chord progression is based on a key.
- Every key is based upon a scale, such as the major scale.
- Each note (degree) of the major scale has an associated chord quality, created using only notes “diatonic to” that scale.
- Diatonic chords can be used build chord progressions that make sense and sound good.
- Triads have 3 notes. Seventh chords have 4 notes, and are much more useful in jazz and blues music.
All righty folks! That’s it for now. Hope it helped!