I–III–IV–iv in B♭ Major

Pattern: I – III – IV – iv   Chords: B♭ – D – E♭ – Ebm

Chord Breakdown

NumeralChordTypeFunction
I B♭ (details) major Tonic
III D (details) major Mediant
IV E♭ (details) major Subdominant
iv Ebm (details) minor Subdominant

Harmonic Analysis

This progression moves through B♭ (Tonic) → D (Mediant) → E♭ (Subdominant) → Ebm (Subdominant).

The I–III–IV–iv progression features a chromatic ascent from I to IV via a secondary dominant III, then darkens with a borrowed minor iv. The III chord (V/vi) adds unexpected brightness while the iv creates a ♭ittersweet descent. This pattern appears in classic rock and singer-songwriter music.

Song Examples

Chord Details

More Progressions in B♭ Major