Bad Guy by Billie Eilish is played in the key of Gm at a beginner difficulty level, originally released in the 2010s. It uses 3 chords — Gm F C — arranged in the i-bVII-IV progression.
About the i-bVII-IV progression
The i-bVII-IV is a modal minor-key progression rooted in the natural minor scale. The bVII chord gives it a folk-rock modal quality that sits outside major-key expectations. You'll hear this shape in modern rock, indie folk, and the moodier Dylan/Stones catalogue.
Playing in the key of Gm
G minor uses Gm, Cm, and D as its primary chords. Gm is a barre; some players prefer to capo up to E-minor shapes.
Related songs
More songs in the key of Gm
Learn to play Bad Guy by Billie Eilish on guitar. It sits in the key of Gm and uses the i-bVII-IV progression with the chords Gm F C.