Three-chord song

A common type of three-chord song is the simple twelve-bar blues used in blues and rock and roll.

The I (tonic), IV (subdominant) and V (dominant) chords (primary triads) together encompass all seven tones of the tonic's major scale.

These three chords are a simple means of covering many melodies without the use of passing notes.

"[2] Lou Reed said "One chord is fine.

"[3] Reed nevertheless wrote many songs with unique or complex chord progressions himself, such as the material on Berlin.