I7 roman degree
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.
Where it lives
0semitones from the tonic
Major mode
dominant 7th
Hear it in context: Gospel Quick-Change
Piano sound loads on first tap. Resolved in the key of C — every chord links to its full analysis.