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Piano Chords Theory

I'd encourage you to learn basic theory for any instrument, but it is definitely easier to see on piano.

Improving chords

We have looked at major and minor chords in the key of C in the previous article. Now we are going to add some notes to create 4-note chords, which sound much, much better and more interesting when you use them together in a song.

Intervals - this is a way of measuring the distance between different notes, and should make music theory easy to understand. It's not here to make things more complicated.

Our C chord is spelt C,E,G - but we could give each note a number, relating to its position in the major scale. The C chord would be 1, 3, 5. It's essential to memorise this!

This formula is the same for every major chord.

More chords - Maj 7, 7, minor


More Chords

If you play a C chord and add a B note, it gives you C maj 7, a four-note chord - Shown in red. Change the top note to B flat, and you have C7. Shown in a strange violet colour. Take that note down one more step and you have C6 (not shown) So C6 just means " C chord with the note A added" - A being the sixth note up in the C major scale.

Minor chords

If we take a C chord, C,E,G or 1,3,5 in intervals and flatten the third, we end up with a C minor. This is shown in green. The formula for this chord is 1, b3, 5. So to change any major chord to minor, just flatten the 3rd. Conversely, to make any minor chord into a major chord, move the 3rd back up one step, or one semitone.

With all these chords play a low C with your left hand to hear the full chord properly.

F maj 7

You can apply these basic rules to all other chords.

F maj7 would be spelt F A C E, left to right.

G7 would be G B D F.

Am7 would be A C E G

Dm7 would be D F A C

Try using these chords in combination with the other chords in C - a very common chord progression is

C Am7 F G7

This is sometimes called a I vi IV V progression ( 1,6,4,5) with the numbers referring to the position of the chords in order in the harmonised scale.

This is very useful, as it enables you to play the same progression in different keys, and can make learning songs much, much easier.


7 chords and major 7 chords are different animals. The top note changes by a semitone, one step.

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So G maj7 uses F sharp, rather than F

C maj7 uses B rather than B flat.

Here's a recap: the formula for a

major chord = 1, 3, 5

minor = 1, b3, 5

maj 7 = 1, 3, 5, 7

7th= 1, 3, 5, b7

6th = 1, 3, 5, 6

It's handy to associate chord sounds with specific songs, and then you can hear what is happening harmonically when you listen or play along with music.

7th chords are the basis of the blues, major 7th chords are found in Gymnopedies by Eric Satie, 6th chords are used in Fool On The Hill by The Beatles.

Other instruments

All this info works for any instrument - the same rules can be used to construct guitar chords, or work out vocal harmonies, or arrange sax parts.

Guitar players in particular will find that this material will help them understand guitar songs better.

Vocalists can use this material for voice training.


Practice playing the chords in C, with the bass note for each chord in your left hand. Play all the notes together, then as an arpeggio. Arpeggio is Italian for "like a harp", playing the notes of a chord one at a time instead of all together, either in an ascending or descending sequence. Here are the chords in C, also known as the diatonic chords, the basis of most songs in any style.

C /// Dm /// Em /// F /// G /// Am /// B dim /// C

Now do the same with the four-note chords with added sevenths:

Cmaj7 /// Dm7 /// Em7 /// Fmaj7 /// G7 // Am7 /// Bm7b5 /// Cmaj7

(The slashes are just there to separate the chords)

The point of this exercise is that all popular songs in many different styles will be harmonised with this list of seven chords. When you learn a new song, you will not be learning everything from scratch, but will already know 90% of the chords that may be used.

More advanced chords

Why do we use more advanced chords instead of the basic major and minor chords?

Generally, adding notes will make the sound of your playing/songwriting more full and more interesting. Chord inversions will also help, in that you can create better voice leading. This is the principle of moving the least number of notes possible in a transition from one chord to the next, making it smooth and predictable in a good way.

For instance, C could be voiced as G,C,E left to right instead of the C,E,G form. To change from C to Am7, just change the left hand bass note from C to A.

When you play C maj7, try voicing it so the B note moves down within the chord structure. It's really good to experiment with voicing every chord in different ways, in other words the notes are the same but in a different order.

C9 is a C7 chord as shown above, with a D note added - only a small change, but generally a big improvement on the basic C7 chord.

Instead of G7, try using F/G - an F chord over a G bass note. This will resolve to C maj7.

You can discover a lot of these things by trial and error, just experimenting with different bass notes etc.

Intervals on piano keyboard


Using Intervals

Here's an example. Taking intervals 1, b3, 5 will make a minor chord, in this case it's Cm. If you add a Bb, the flat 7 interval, you have a minor 7th chord, Cm7.


Jon Green (author) from Frome, Somerset, UK on April 18, 2012:

If you give me a list of chords I'll do a hub on them.

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