# The I - IV - V Chord Pattern

Before you learn how to form certain chords you must first learn about scales. A scale is a series of notes that go in an ascending and descending manner. For every scale (major or minor) there are 7 notes, for example in the key of C the notes are C - D - E - F - G - A - B. The 8th note (in this example will be C) goes back to the root note but an octave higher.

Each note of a scale has a corresponding number from 1 to 7. So for the key of C it will be as follows:

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

In order to make a major triad, you will play the 1st + 3rd + 5th notes of a major scale. In our example it is C - E - G, that's the C major chord.

Let's have another example this time using the C minor scale:

C = 1
D = 2
Eb = 3
F = 4
G = 5
Ab = 6
Bb = 7

In order to make a minor triad, you will play the 1st + 3rd + 5th notes of a minor scale. In our example it is C - Eb - G, that's the C minor chord.

Note: For the next entry we will omit the 7th and 8th notes to make it less confusing.

## Roman Numerals

Sometimes instead of numbers, Roman Numerals are used. We go back to our example and use a Roman Numeral for each note in the key of C:

C = I
D = ii
E = iii
F = IV
G = V
A = vi

Roman numeral I refers to the chord built on the first note of the C major scale. Roman numeral II refers to the chord built on the second note of the C major scale, and so on. If you notice, some of the Roman numerals are capitalized while others are not. Uppercase Roman numerals pertain to a major chord, while lowercase Roman numerals pertain to a minor chord. Uppercase Roman numerals with a (+) symbol refer to an augmented chord. Lowercase Roman numerals with a (o) symbol refer to a diminished chord.

## The I, IV, and V Chord Pattern

For each key, there are 3 chords that are played more than others known as "primary chords." The I - IV - V chords are built from the 1st, 4th and 5th note of a scale.

Let's take the key of C again as an example, looking at the illustration above, you will notice that note I on the key of C is C, note IV is F and note V is G.

Therefore, the I - IV - V chord pattern for the key of C is:
C (note I) = C - E- G (1st + 3rd + 5th note of the C scale)
F (note IV) = F - A - C (1st + 3rd + 5th note of the F scale)
G (note V) = G - B - D (1st + 3rd + 5th note of the G scale)

There are many songs that have been written using the I - IV - V chord pattern, "Home on the Range" is one example. Practice playing the I - IV - V chord pattern for every major key and listen to how it sounds as this might inspire you to come up with a great melody for your song.

Here's a handy table to guide you.