1The IV with a common tone on top
IV in B majorGoing from B to Eadd9, the ninth of the IV is the fifth of the I. Keep that note on top of both chords and it ties them together, which is much of why the pair sounds so good.
Listen for: The top note never moves: the fifth of the I, then the ninth of the IV. On the plain IV it drops a whole step.
Heard in“Overture” from Tommy
