I–♭VI–♭VII–I in B♭ Major

Pattern: I – ♭VI – ♭VII – I Chords: B♭ – G♭ – A♭ – B♭

Chord Breakdown

Numeral	Chord	Type	Function
I	B♭ (details)	major	Tonic
♭VI	G♭ (details)	major	Submediant
♭VII	A♭ (details)	major	Subtonic
I	B♭ (details)	major	Tonic

Harmonic Analysis

This progression moves through B♭ (Tonic) → G♭ (Submediant) → A♭ (Subtonic) → B♭ (Tonic).

The I–♭VI–♭VII–I progression borrows two chords from the parallel minor to create a heavy, powerful major-key riff. The ♭VI and ♭VII provide dark, chromatic contrast before the triumphant return to the major tonic. This pattern is a staple of power metal and hard rock anthems.

Song Examples

Enter Sandman, Metallica
Thunderstruck, AC/DC

Chord Details

B♭ G♭ A♭

More Progressions in B♭ Major

I–IV–V–I I–V–vi–IV I–vi–IV–V ii–V–I I–IV–V I–♭VII–IV vi–IV–I–V I–V–vi–iii–IV–I–IV–V I–IV I–V IV–V IV–I