Blues Shuffle Turnaround I7-IV7-V-I7
Piano sound loads on first tap. Resolved in the key of C — every chord links to its full analysis.
The classic 12-bar blues shuffle skeleton, dominant sevenths throughout, closing on V before looping back to a tonic that's already a dominant chord itself — the triplet-feel loop under most blues, rock 'n' roll and rockabilly.
What each degree does
The tonic turned dominant — adding a minor 7th makes I the V OF IV, tonicising the subdominant. That blues-and-gospel turn that pushes toward IV.
The subdominant as a dominant — IV with a minor 7th, a bluesy colour that pulls toward I by the 'backdoor' or tonicises bVII.
Tension pulling home — the chord that 'wants to resolve' to I; it closes or opens sections. The dominant, the engine of the key.
The tonic turned dominant — adding a minor 7th makes I the V OF IV, tonicising the subdominant. That blues-and-gospel turn that pushes toward IV.