Primary Chords (I-IV-V)

In a major key, the I, IV, and V chords are called the primary chords. These are all the major chords in the key. They are the scaffolding around which major key chord progressions often revolve. Many songs consist only of primary chords.

Basic I-IV-V progression

This is a basic I-IV-V chord progression using E-shape major chords.

Dominance of the perfect fifth

• The I chord, or tonic chord, is the most important chord in a key. It's home; the chord all others are defined in relation to, a place of rest and resolution, and often the first and last chord in a song.
• The V chord is a perfect fifth above the I, so it's called the dominant chord. (The perfect fifth is the dominant interval.)
• The IV chord is a perfect fourth above the I (and also a perfect fifth below it), so it's called the subdominant chord. (The perfect fourth is the subdominant interval.)

The perfect fifth is the most universal musical sound in the world, across cultures and throughout history. So these chords, a fifth above and a fifth below the tonic, are perhaps the most common in all of Western music.

Practice progression

It's worth practicing the I-IV-V chords in every combination, because they will likely be some of the most common chords you play. This progression includes a change between each of the three chords, in both directions, so you can practice every combination of changes between them.

Practice chord changes with pentatonics

Once you have the chord changes down, practice playing the E-shape major pentatonic over various primary chord progressions. This diagram gives just one example. Use your ears and your creativity to come up with others.