Seat-of-the-Pants-Music-Theory: What are the three chords most commonly used in a key?

Now that you know both how to build a scale and how to build a chord using that scale, let’s ask what are the three chords most commonly used in a key? 

At the simplest level, I view music as a sequence of notes (called the melody) played or sung in the context of a particular sequence of chords.  If you use the wrong melody notes for the song you want to play, it just won’t work.  Think how it would sound if you sang the words to Mary Had a Little Lamb to the melody for Twinkle Twinkle Little Star.  Just doesn’t make sense, does it? 

The same is true for the chord sequence used as context for the melody.  If the chords aren’t the right ones and in the right order, the song won’t sound like the song it’s supposed to be.

For those of you with some musical experience, you have probably already discovered that a simple song in the key of G will probably use G chords, C chords, and D chords.  Other chords may be used but the most common ones in the key of G will be G, C, and D.  The best reason I can offer as to why these are the three chords most commonly used is that those particular chords just sound good to the human ear.

Let’s use a simple, three chord, key of G version of Amazing Grace as our work in progress.  The key of G chord sequence for Amazing Grace follows:

CHORD                                 G                             G                             C                             G
LYRIC                     A             maz        ing          grace     how       sweet   the         sound

CHORD                                 G                             G                             D                             D
LYRIC                     That       saved    a              wretch  like         me…………………………

CHORD                                 G                             G                             C                             G            
LYRIC                     I               once      was        lost         but         now       am          found

CHORD                                 G                             D                             G                             G
LYRIC                     Was       blind      but         now       I               see………………………….

To summarize, the chord sequence for Amazing Grace in the key of G is as follows:

                G             G             C             G
                G             G             D             D
                G             G             C             G
                G             D             G             G

OK, so you’ve learned the chord sequence for Amazing Grace in G and now head out to a jam session.  But it turns out your jam partners want to play it in A!  Now what?  What chords do you play in A? 

To understand how to use scales to predict what chords to use in A, let’s first number the G scale tones:

                G             A             B                         D             E              F#           G
                            2              3                        5              6              7             8

I have marked the G, the C, and the D scale tones and their corresponding numbers 1, 4, and 5 in red text.  The chord sequence for Amazing Grace can now be presented in numbers where 1 refers to a G chord, 4 to a C chord, and 5 to a D chord:

                1              1              4              1
                1              1              5              5
                1              1              4              1
                1              5              1              1

Now to convert the chord sequence to the key of A.  First, recall the A scale.  Then assign numbers to the tones of that scale.

                A             B             C#           D             E              F#           G#          A
                1              2              3             4              5              6              7            8

Now substitute letters from the A scale for the number sequence for Amazing Grace: 1 becomes A, 4 becomes D, and 5 becomes E.

                A             A             D             A
                A             A             E              E
                A             A             D             A
                A             E              A             A

And, voila’, you have transposed from the key of G to the key of A!

In summary, the most commonly used chords in a particular key will be the ones built on the 1st, the 4th, and the 5th tone of its scale.  Literally hundreds of songs from a wide range of styles can be played using just these three chords.  Take a look at this partial list of three chord songs:

All the Good Times are Past and Gone bluegrass
Amazing Grace traditional  
Bad Moon Rising Credence Clearwater 
Blowing in the Wind Peter, Paul & Mary
Blue Moon of Kentucky bluegrass
Blue Ridge Cabin Home bluegrass
Blue Suede Shoes Carl Perkins
Bury Me Beneath the Willow bluegrass
Cabin Home on the Hill bluegrass
Cecelia Simon & Garfunkle
Columbus Stockade Blues bluegrass
Cripple Creek bluegrass
Crying holy bluegrass
Doing My Time bluegrass
Drink Up and Go Home bluegrass
Faded Love bluegrass
Gone Gone Gone bluegrass
Good Hearted Woman Waylon & Willie
Great Balls of Fire Jerry Lee Lewis
Happy Birthday traditional  
Head Over Heels bluegrass
Hey, Hey Good Lookin’ Hank Williams
Honey, You don’t Know My Mind bluegrass
Honky Tonk Woman Rolling Stone
How Mountain Gals Can Love bluegrass
I Just Think I’ll Stay Around bluegrass
I Saw Her Standing There Beatles
I Saw the Light bluegrass
I Wonder Where You Are Tonight bluegrass
If I Should Wander Back Tonight bluegrass
I’ll Go Steppin’, too bluegrass
I’ll Never Love Anybody but You bluegrass
I’ll Never Shed Another Tear bluegrass
I’m So Lonesome I Could Cry Hank Williams
Johnny B Goode Chuck Berry
King of the Road Roger Miller
Kum Ba Yah traditional  
Lay Down Sally Eric Clapton
Leaving on a Jet Plane Peter, Paul & Mary
Mammas, Don’t Let Your Babies Willie Nelson
Me and Bobby McGee Janis Joplin
Momma Don’t Dance Loggins and Messina
Mountain Dew bluegrass
Oh Susanna traditional  
Old Time Rock & Roll Bob Seger
Rock Aroung the Clock Bill Haley & the Comets
Roll Out the Barrel Traditional Polka
She’ll be Coming Round the Mtn traditional  
Silent Night traditional  
Surfin’ USA Beach Boys
Teach Your Children Crosby Stills Nash & Young
Teardrops on my Guitar Taylor Swift
Twist and Shout Beatles
When the Saints Go Marching In traditional  
White Dove bluegrass
Will the Circle Be Unbroken bluegrass
You Are My Sunshine traditional  
Your Cheating Heart Hank Williams

Now for the bad news… none of this discussion tells you in what order to play the chords for a particular song nor for how many beats to play a particular chord.  Arrggg!  I’m sorry to say I don’t think it is possible to understand those concepts from just talk.  I think it will require some experimentation with your instrument.  This experimentation is one aspect of ear-training. 

As part of your experimentation, play the 1, the 4, and the 5 chords of a key on your instrument.  Listen to how the sound of each chord relates to the sound of the other chords.  Then start applying those sounds to a particular song.  Take for example the first couple of lines of ‘You Are My Sunshine’.  This particular tune starts on the ‘1’ chord. In the key of G that means we start on a G chord.  Play a G chord on you instrument and sing these two lines.  Is there is a chord change anywhere during either line (hint: there is).  What word are you singing when the chord changes?  (If you said ‘hap’ in the second line, you got it!). 

You     are       my       sun       shine    my       on        ly         sun       shine
You     make    me       hap      py        when   skies    are       grey

So what chord will you use at ‘hap’?  You have a 50-50 chance of guessing right.  You know you started with a ‘1’ (G) chord.  You also know we are talking about 3 chord songs.  If the chord changed (and it did) it has to be to either the ‘4’ (C) chord or the ‘5’ (D) chord, doesn’t it? 

Try singing these two lines and play chords in the background.  Start with a G chord.  When you get to ‘hap’ try playing a D chord.  Does it sound right?  Do it again and try a C chord on ‘hap’.  Does that sound right? 

If you want some help with this project, we can set up a lesson or two to ease your path towards understanding all this.  You can either call 513-607-1874 or email me at  to schedule a meeting.  We can meet at either the Mt. Healthy studio or the Oxford studio.  Although I haven’t tried it before, it is also possible we might have this discussion via Skype.   We can give it a shot anyway. 

Thanks for following my Seat-of-the-Pants-Music-Theory blog.  Stay tuned for future posts with some instrument specific suggestions about how to use scales and chords to embellish a melody.