The Must Know Piano Chords

As you probably know, there are thousands and thousands of different chords - everything from basic major chords to minor 7ths to 13ths to suspensions to poly-chords.

But meanwhile, there are 3 chords that you absolutely, positively have to know. If you don’t know these three, there’s hardly a song in the whole world that you could play. But by knowing just 3 chords, you can play hundreds, if not thousands of songs.

I - IV - V

In every key, there are 3 chords which are known as “primary chords” - chords that occur way more than other chords. They are like family members of that particular key. There are groups of notes built on the 1st note of the scale, the 4th note of that scale, and the 5th note of that scale. Those are 3-note chords called “triads”. Later we will get into 4 and 5 note chords.

For example, here is the C scale on the keyboard. It runs from C up to C an octave higher. The I chord is built on the first note of the C scale, and so on.

So if I build a chord on the I - every other scale note up from C, the chord is C E and G, known as the C major chord.

If I build a chord on the IV, every other scale note up from F, the chord is F A and C, known as the F major chord.

If I build a chord on the V, every other scale note up from G, the chord is G, B, and D, known as the G major chord.

If you haven’t already noticed, these 3 chords contain ALL the notes in the C scale.

So any melody or song in the key of C, as long as it just uses the 8 notes of the scale, can be harmonized by playing one of those 3 chords!

So in any given key you can play, there are primary chords, which are chords that occur way more than other chords. They are like family members to a particular key.

Let’s say you have 3 people in your family. Your spouse, your child, and you. On the same block, down the street lives your cousin and her family. At any given moment, who are the most likely people to be in your house?

If I had to guess, it would probably be your spouse, your child, or you. It might be your cousin down the street, but there's a much better chance of that your direct family members would be there.

It’s the same way with chords. In any given key, there are 3 family members that are residents of that key: the I chord, the IV chord, and the V chord. They are the most likely chords to occur in any given key.

Does that mean that there are just 3 chords in a song? No, but there are literally hundreds of songs that are made up of just 3 chords.

The Primary Chords of All Major Keys

Here are the primary chords of all the major keys. Remember that the primary chords are the I chord, the IV chord, and the V chord based on the scale of that particular key.

Key of C:

C, F, G

Key of Eb:

Eb, Ab, Bb

Key of E:

E, A, B

Key of F:

F, Bb, C

Key of Gb:

Gb, Cb, Db

Key of G:

G, C, D

Key of Ab:

Ab, Db, Eb

Key of A:

A, D, E

Key of Bb:

Bb, Eb, F

Key of B:

B, E, F#

Do you have to know all these chords in all these keys? No. You can choose to play in just one key, or just a few keys. But what you must know is the 3 chords in whatever key you want to play in.